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Copyright N°__ 

COPYRIGHT DEPOSm 



















GRGGG 




( 

HYGIENE 
BY EXPERIMENT 

A SERIES OF PROBLEM STUDIES 1 ~ 

IN HYGIENE, FOR PUPILS IN 
INTERMEDIATE GRADES AND 
IN JUNIOR HIGH SCHOOLS 

* * * 

By F. M. Gregg 

Head of the Department of Psychology 
Nebraska Wesleyan University 
Formerly Teacher of Physiological Sciences 
Nebraska State Teachers-[College 



Yonkers-on-Hudson , New York 

WORLD BOOK COMPANY 
1923 









WORLD BOOK COMPANY 

THE HOUSE OF APPLIED KNOWLEDGE 
Established, 1905, by Caspar W. Hodgson 

Yonkers-on-Hudson, New York 
2126 Prairie Avenue, Chicago 

Hygiene by Experiment is the outgrowth 
of work in the classroom. It consists of a 
series of live studies which require obser¬ 
vation and investigation on the part of 
the pupil. The point of view is that of 
nature study, and the method is essen¬ 
tially the project method. Every experi¬ 
ment and every study has been tried in 
numerous schools, under Professor Gregg’s 
supervision. The results have been good, 
and the method commends itself to the 
modern teacher. World Book Company 
takes pleasure in presenting this text of a 
new type in the study of hygiene, con¬ 
fident that it deserves its place among 
“Books that apply the world’s knowledge 


to the world’s needs” 





GHE-2 


Copyright 1923 by World Book Company 
Copyright in Great Britain 
All rights reserved 
PRINTED IN U. S. A. 


©C1A703212 


APR -8 73 


V 








M 

<\l 


PREFACE 


During the generation or more that the subject of 
physiology and hygiene has been required in the courses 
of study in our public schools, three points have been 
made clear, as follows: 

1. That we need to lay increasing emphasis on hygiene 
and sanitation and less on physiology and anatomy. 

2. That our aim must be to develop boys and girls 
who are not only intelligent but also physically fit. 

3. That our methods must be made more effective. 

This textbook seeks to further the purposes that these 

three points indicate. It is the outgrowth of a good many 
years of experimentation with teaching methods in ele- 
mentary hygiene in the training schools of the Peru, 
Nebraska, State Teachers College and of the Teachers 
College of Nebraska Wesleyan University. Its immediate 
predecessor has been the author’s manual for teachers, 
entitled Hygiene as Nature Study. It seeks to give the 
pupil: 

First, the necessary motivation for the study of the 
subject through appeal to his normal interests; 

Second, the necessary sense experience by which to 
interpret the terms of the printed page; and 

Third, the necessary stimulus to guarantee the fixing of 
proper health habits. 




in 


CONTENTS 


PAGE 


A Talk with the Teacher. vi 

PART ONE 
Habit Hygiene 

A Word with the Boys and Girls. I 

STUDY 

1. Taking a Measurement of Yourself. 3 

2. Making the Body Strong and Straight.n 

3. Good Air and How to Breathe It.18 

4. Learning about Your Breathing Organs.27 

5. The Teeth and Their Care.36 

6. What and How to Eat and Drink.43 

7. Tea, Coffee, Alcohol, and Tobacco.52 

8. The Blood and Its Circulation.59 

9. Caring for the Skin. 64 

10. Taking Care of the Finger Nails, Hair, and Scalp .... 7 ° 

11. Uses of Clothing .74 

12. The Brain as the Home of the Mind.81 

13. Taking Care of Your Eyes and Ears.87 

14. What to Do in Accident and Emergency.92 

PART TWO 
Community Hygiene 

To the Boys and Girls.95 

15. Bacteria, the Smallest of Plants.97 

16. Protozoa, the Smallest of Animals.105 

17. How Your Body Fights Its Germ Enemies.no 

18. How You Can Help to Combat Germs.118 

19. Diseases Caused by Bacteria.123 

20. Diseases Due to Plants Other than Bacteria.131 

21. Diseases Caused by Protozoa.135 

22. Diseases Due to Simple Animals Other than Protozoa . . 139 

23. Mosquitoes as Carriers of Germs.142 

24. Flies as Carriers of Germs.148 

25. Quadrupeds as Disease Carriers.155 

26. Disposal of Garbage, Rubbish, and Waste.160 

27. Good Water for Drinking .164 

28. Community Care of the Sick.170 

29. Inspection of Foods and Supervision of Food Production . 175 

30. Surveys of Schoolhouse and Home.180 


IV 
































CONTENTS 


v 


PART THREE 

Personal Hygiene: Physiology 

STUDY PAGE 

To the Boys and Girls.187 

31. Your Foods.189 

32. How Foods Are Digested.197 

33. How Foods Serve the Body.202 

34. Stimulants, Narcotics, and Drugs.208 

35. The Air and Breathing.215 

36. Respiration and the Organs of Respiration.226 

37. Blood and Lymph.233 

38. The Circulation of Blood and Lymph.240 

39. Common Colds and How to Avoid Them.247 

40. The Skin and Bathing: Clothing .252 

41. Ventilation and Body Heat.256 

42. Sources, Forms, and Exits of Body Waste.266 

43. Bones and Joints.278 

44. Muscles: Posture, Exercise, and Fatigue.283 

45. Behavior and the Nervous System.289 

46. The Senses and Their Meaning.296 

47. Health Problems.305 

A Final Word With the Boys and Girls.309 

APPENDIXES 

A. A Plan for a Health Club .311 

B. Health Chores and Record Chart.314 

C. A Score Card for Hygienic Living.316 

D. Apparatus, Materials, and Supplies for the Course . . . .318 

E. Reference Pamphlets for Pupils and Teacher.321 

F. Suggested Reference Books.323 


























A TALK WITH THE TEACHER 


In the following studies in hygiene, Part One is de¬ 
signed for use in Grade 5 or 6; Part Two, for Grade 6, 

7, or 8; and Part Three for Grade 7, 8, or 9. The work 
in each of these parts may readily be made to occupy a 
half year of school time. The work can be given on suc¬ 
cessive days through a half year of school, or it can be 
taken up on alternate days or weeks throughout the year. 
Many teachers prefer the latter arrangement, since it 
gives a longer opportunity to help fix the health habits 
that it is desired to set up. 

It is the conviction of the author that every major 
and even minor topic in the subject of hygiene for the ele¬ 
mentary grades should be approached through concrete 
observation and experiment by the pupil. These concrete 
studies can then be followed up by as much further book 
work as time and resources will permit. The vital point 
to remember is that the experiments and observations 
are to be done before and not after the other readings. 

It should be said with a good deal of emphasis that, to 
insure the most satisfactory results, the teacher needs to 
keep looking well ahead so as to start the assembling of 
materials for the successful execution of the studies that 
are to follow in the work with the class. Just a little at¬ 
tention of this kind will fortify the teacher against em¬ 
barrassments that always come from neglect of details. 

The teacher should plan from the very first to give her 
pupils opportunity to provide as many of the experi- . 
mental materials as possible and to assist in the experi¬ 
ments. This at once increases the pupils’ interest and 
decreases the teacher’s labor. How much of the work of 
any experimental study shall be done by the pupils 


VI 


*1 TALK WITH THE TEACHER 


Vll 


individually , and how much shall be done as a class 
demonstration , will be determined according to conditions 
in the individual school. 

While Parts One, Two, and Three of these studies have 
been prepared to be used with Ritchie-Caldwell’s Primer 
of Hygiene , Ritchie’s Primer of Sanitation , and Ritchie’s 
Primer of Physiology , respectively, any other authorities 
on the successive topics may be utilized. Indeed, a num¬ 
ber of such authorities may well be employed, and the 
hygiene work can be carried on under the plan of the 
socialized recitation. On pages 321-324 are lists of 
reference sources, and the list of materials needed for 
the course is given in Appendix D. 

Study carefully the matter contained in the Appendixes 
at the back of the book. The suggestions these contain 
will help in solving your most important problem, that of 
getting boys and girls to put into practice the principles 
that are fundamental to good health. 



PART ONE 
Habit Hygiene 

A WORD WITH THE BOYS AND GIRLS 



Fig. i. A morning inspection. The inspector for the day is the pupil 
who had the best record for cleanliness on the preceding day. In this 
school, if a pupil is not clean when he comes to school, he is sent to the 
school lavatory to wash himself. 


In parts of Europe it used to be the custom for a grand¬ 
mother on Christmas morning to give out to the little 
girls of the household a big ball of yarn, called a “wonder 
ball.” What really made the ball big was not so much the 
yarn with which it was wound, as the number of Christ¬ 
mas presents hidden within it. 

In making up the ball the very finest present was 
placed at the center. After this had been wound over with 
yarn, other presents of less value were wound in at inter¬ 
vals, and the least attractive present of all was covered 


i 








HYGIENE BY EXPERIMENT 


2 

with ya *n at the last. But there was something about this 
Christmas gift that made it different from gifts as we 
know them, for each girl who received a wonder ball was 
expected to knit stockings from the yarn and to uncover 
the presents one by one as she knitted. 

To some young people such a gift as the wonder ball 
might not seem very desirable, because of the work and 
the delay in getting at the presents. But the girl who 
received a wonder ball gained a great deal in the mastery 
of a useful art and had the fun of uncovering surprising 
presents of increasing value until the best present of all 
at last lay before her wide-open eyes. 

In the little book you are now to study, you are to have 
experiences somewhat like that of the child with a wonder 
ball, for you are to learn how to do a great many different 
things, and each time you do what you are told to do, a 
surprising result will follow. Not only will you learn 
many of the arts and habits that will keep your bodies 
strong and well, but you will be rewarded with new knowl¬ 
edge about many things. In the end there will come to 
you the richest of all gifts to mankind — bodies that are 
robust and vigorous, and that are capable of performing 
the many acts necessary to make life wonderfully worth 
while. 


STUDY ONE 


TAKING A MEASUREMENT OF YOURSELF 

The Greeks who lived some 2000 years ago were a peo¬ 
ple who took great pride in having strong, beautiful bod¬ 
ies. You may have seen copies of statues of their great 
men and noted what fine-looking people the Greeks must 
have been. One of the rather numerous gods and 
goddesses that they worshiped was called Hy-ge'ia , the 



Fig. 2. Taking the physical measurements of a boy at 
school. The tape is in place for measurement of the 
chest, and a lung tester stands ready for use. 


3 
























4 


HYGIENE BY EXPERIMENT 


Goddess of Health. The word “hygiene” comes from the 
Greek word for “healthful.” You are about to take up the 
study of hygiene, a subject which teaches how to keep the 
body strong and well. 

Your first study is to be of yourself, so that you can be¬ 
gin to practice one of the first maxims of the wise and 
strong Greeks, “Know thyself.” With the teacher, you 
will have to work out the best plan for taking these 
measurements. But be sure to take them very accu¬ 
rately, for a good many of the measurements you will 
want to take later on, some of them as often as once a 
month, just to see how much growth you can make. 

Exercise I. Getting Your Measurements 

1. The key to the table. 

A. What is your height in inches? 

B. What is your weight in pounds? 

2. What to measure. (Note. In the table below insert 
only those measurements called for in Exercise II.) 



YOUR 

RECORD 

STANDARD 

FOR YOUR 
BUILD 

PLUS 

CREDITS 

MINUS 

CREDITS 

A. Weight in pounds. 





B. Shoulder girth. 





(taken at biggest part) 

C. Girth of relaxed right arm. .. 





(at middle of upper arm) 

D. Girth of contracted right arm 
(upper arm as big as possible) 

E. Right arm expansion. 





(difference in preceding two) 
F. Girth of relaxed left arm. . . . 





(at middle of upper arm) 

G. Girth of contracted left arm 
(upper arm as big as possible) 






























TAKING A MEASUREMENT OF YOURSELF • 5 



YOUR 

RECORD 

STANDARD 
?OR YOUR 
BUILD 

PLUS 

CREDITS 

MINUS 

CREDITS 

H. Left arm expansion. 





(difference in preceding two) 
I. Waist girth. 





(at smallest place) 

J. Hip girth. 





(at biggest place) 

K. Right thigh girth. 





(biggest place, standing) 

L. Left thigh girth. 





(biggest place, standing) 

M. Average thigh girth. 


• 



N. Right calf girth. 





(biggest place, standing) 

0. Left calf, standing. 





(biggest place, standing) 

P. Average calf girth. 





Q. Girth of neck, lower half.. . . 





R. Girth of expanded chest.... 





(a little below armpits) 

S. Girth of contracted chest... . 





(a little below armpits) 

T. Chest expansion. 





(difference in preceding two) 
U. Total lung capacity. 





(spirometer measurement) 






3. What is your final score of physical measurements? 

Exercise II. Getting Your Physical Standards 

1. Taylor’s tables of standards. The following table 
of standards, for people of five different types of build, 
were prepared by Charles K. Taylor, of the Depart¬ 
ment of Standards of Carteret Academy, for the Cen¬ 
tury Company’s book, The Boy's Camp Manual. (The 
































6 


HYGIENE BY EXPERIMENT 


tables are here given only in part. The full tables may be 
obtained of Professor Taylor at the Carteret Academy, 
Orange, N. J., by the purchase of his little book, Physical 
Standards for Boys and Girls. 


A. Table for Males of Slender Build 


Height 

Weight 

Shoulder 

Girth 

Chest 

Girth 

Chest 

Expansion 

Right Arm 
Relaxed 

Difference 

Left Arm 

Relaxed 

Difference 

Waist 

Hips 

Thighs 

Calves 

5i 

54 

28 y 2 

22 p2 

2X 

6X 

7 A 

6 

X 

19X 

23X 

14 

9'A 

52 

56 

2m 

23 

24< 

6X 

A 

6 % 

X 

19X 

23X 

14 A 

9 X 

53 

58 

29 A 

23X 

2X 

6 A 

1 

6 A 

X 

20 

24 

15 

10 


B. Table for Males of Slender-Medium Build 


| Height 

Weight 

Shoulder 

Girth 

Chest 

Girth 

Chest 

Expansion 

Right Arn 
Relaxed 

Difference 

Left Arm 
Relaxed 

Difference 

Waist 

Hips 

Thighs 

Calves 

5i 

56 

29X 

23X 

2X 

6 A 

7 A 

6X 

X 

20 

25 

*4 7 A 

10A 

52 

59 

29X 

23X 

2 A 

6 A 

1 

6 H 

X 

20X 

25X 

15X 

10A 

53 

61 

3°X 

24X 

2 A 

6 H 

1A 

6K 

A 

20 A 

26 

15X 

10A 


C. Table for Males of Medium Build 


| Height 

Weight 

1 

Shoulder 

Girth 

Chest 

Girth 

Chest 

Expansio 

I Right Arr 
1 Relaxed 

Difference 

Left Arm 
Relaxed 

Difference 

Waist 

Hips 

Thighs 

Calves 

56 

75 

34 X 

26X 

3 % 

7 X 

1X 

7 X 

1 x 

23X 

28 

I 7 X 

11A 

57 

78 

34 A 

26X 

3 A 

l 7 A 

iX 

7A 

i A 

23X 

28X 

17X 

n A 

58 

83 

35A 

27 H 

3 A 

8 

iX 

7 X 

1 A 

24X 

29 

18 

11X 

















































































TAKING A MEASUREMENT OF YOURSELF 


/ 


D. Table for Males of Medium-Heavy Build 


Height 

Weight 

Shoulder 

Girth 

Chest 

Girth 

Chest 

Expansion 

Right Arm 

Relaxed 

Difference 

Left Arm 

Relaxed 

Difference 

Waist 

Hips 

Thighs 

Calves 

5i 

62 

3iX 

25X 

2 A 

7 'A 

r 

6 yi 

yi 

21K 

26 

16 yi 

11 

52 

66 

31 H 

25K 

3 

7X 

1 a, 

7 l A 

1 

22 

26 X 

16 yi 

11 A 

53 

68 

32 

26 

3 

7H 

1 a 

7% 

1 

22 X 

27 

16X 

11 A 


E. Table for Males of Heavy Build 


Height 

Weight 

Shoulder 

Girth 

Chest 

Girth 

Chest 

Expansion 

Right Arm 
Relaxed 

Difference 

Left Arm 
Relaxed 

Difference 

Waist 

Hips 

Thighs 

Calves 

5 i 

65 

32 

26 

3 

7 A 

1 A, 

7 A 

1 

22 % 

27 

16 A 

nX 

52 

69 

32X 

2 6A 

3 

7 A 

1A 

7A 

1 

23 A 

28 

16 X 

11X 

53 

74 

33 

27 A 

3 'A 

7 5 A 

1A 

7A 

1 A 

23 X 

28 A 

1 7A 

1 2 A 


2. How to use the tables. Locate in one of the five 
tables above, the height-weight line that is nearest to 
your own height and weight. The table in which that line 
occurs will give you your type of build. If you are in 
doubt as to which table is nearest for your records, try 
the nearest line in each of two tables, and the one that 
gives you the highest total credit is the one to go by. 
From this table figure out your own record of standards, 
so far as the table gives these standards. Enter these 
standards in a table in your notebook corresponding to 
the table on page 4 in this book. What is your type of 
build? 

3. Marking your scores. Mr. Taylor recommends the 
following method of scoring, taking 100 as the ideal score 
that any one should have: 






















































8 


HYGIENE BY EXPERIMENT 


A. In your measurements for the girth of the shoul¬ 
ders, the expanded chest, each arm, the waist, and the 
average of the calves, find how many quarters of an inch 
your measurements are different from the standard for 
each of your seven measurements. Put this number for 
each measurement in the column of plus credits, if your 
measurement is above the standard; put it in the 
column of minus credits, if it is below the standard. 

B. In the differences in the two measurements of your 
arms and chest (chest expansion), find how many eighths 
of an inch each of your measurements is different from 
the corresponding standard. Put this number for each 
measurement in the column of plus credits, if your meas¬ 
urement is above the standard; put it in the column of 
minus credits, if it is below the standard. 

C. In the cases of hip and average thigh measurements, 
allow one score point to be placed in the plus or minus 
credit column, as the case may be, for each half inch your 
measurements differ from the standard. 

4. Getting your final score. Add up the scores in the 
column of plus credits, and those in the column of minus 
credits, and find the difference between these two sums. 
If there are more plus credits than minus credits, add the 
difference in the sums to 100. If there are more of the 
minus credits subtract the difference in the sums from 
100. The result in either case will give your final score. 
What is it? 

5. Correcting your defects. Study carefully all the 
measurements in which you have a minus score, and in 
your notebook make a record of what you are going to do 
by way of practice to bring your scores all up to the stand¬ 
ard for you. 


TAKING A MEASUREMENT OF YOURSELF 


9 


Exercise III. Making a Notebook 

Reference has been made in the foregoing exercises to 
your notebook. A notebook is an important part of this 
course. 

1. The kind of notebook to have. The paper for your 
notebook should be about 7 inches by io inches in size. 
However, your teacher can advise you about that. It is 
best to have loose sheets so they can be put into your 
notebook as you need them. 

2. What to write in your notebook. In this textbook 
you will find that for each paragraph that is numbered, 
there are one or more questions to be answeied or there 
is something to be done. For each of the Studies you 
should copy in your notebook the title of the Study and 
then the titles of the Exercises. For each Exercise you 
should write down the number and title of each para¬ 
graph, following the paragraph title with the question or 
questions found at the end of each paragraph. Then, 
after the questions you have copied, write the answers 
you have found for the questions. 

3. Following up a Study. At the end of each Study 
there is usually a list of Questions for Investigation. 
After > r ou have written the answer to the last of these 
questions, you should write down any information you 
have gathered on the Study and that you have not al¬ 
ready written about. 

4. How to finish a Study. It will be most interesting 
to finish each Study with scrapbook pictures and original 
drawings. You may cut out of magazine advertisements 
pictures that will illustrate health activities and instru¬ 
ments, or you may make appropriate pictures of your 
own. In either case, be sure to write a good title under 
the picture. Perhaps your teacher will furnish you with 


10 


HYGIENE BY EXPERIMENT 


some hectographed sketches or tables that you may use. 
The more original you can make this part of your book, 
the better it will be. 

5. What to put in the back of your notebook. Among 
the last of the questions asked in each Study there is 
usually one calling for the list of health habits you should 
form. In an appendix at the back of your notebook, you 
should keep a list of all the health rules that you and the 
rest of the class and the teacher agree are the best ones 
to follow. This list will grow as you continue your study 
of hygiene. Try very hard to practice all these rules of 
health until they become habitual with you. The organ¬ 
ization of a Health Club will help you to do this. In 
Appendix A of this book you will find a plan for such an 
organization. 


STUDY TWO 

MAKING THE BODY STRONG AND STRAIGHT 

You have surely heard the remark, “He walks like a 
soldier,” and perhaps you have seen some man who served 
long as a soldier, walking as straight as if he were still in 
the ranks. You can recognize a well-drilled soldier almost 
as quickly by his excellent body posture as by his uni¬ 
form. Fortunately for you, unless you have suffered some 
injury, you can walk as straight as any soldier, if you try 



Figs. 3, 4, and 5. Three types of posture. The lines show the three 
“posture angles.” Which type of posture do you have, and which type 
would you like to have? 


11 
























12 


HYGIENE BY EXPERIMENT 


hard enough. But to do so will take some effort, and it is 
important that you start practicing a better posture at 
once. 


Exercise I. The Work of Muscles 

1. Getting ready to study a muscle. Take a piece of 
rubber band about 2 inches long and yi of an inch wide, 
and stretch it to twice its first length. How does a rubber 
band change in thickness and width when it is stretched? 

2. How muscles hold bones in place. Take two such 
rubber bands, each about 2 inches long and of an inch 



Fig. 6 . A clothespin with elastic bands attached, ready for mounting. 

wide, and tie them firmly in place above the head of a 
clothespin, as shown in Figure 6. At the top of a section 
of broomstick, hollow out a pit into which the round 
head of a clothespin will fit. With rubber bands and 
thumb tacks, fasten the clothespin to the piece of broom¬ 
stick, at front and back, as shown in Figure 7. By 
shifting the position of one or the other of the thumb 
tacks, the clothespin can now be made to point in dif¬ 
ferent directions. 

3. How a man stands up. If you want to make a more 
complete showing of the way muscles work in the 
human body, take a piece of soft wood 1 inch thick, 2 
inches wide, and 5 inches long, and cut suitable pits in 
the ends. Now, fasten clothespins for arms and legs and 













MAKING THE BODY STRONG AND STRAIGHT 13 


a knob of wood for the head, and thus make a wooden 
man such as is shown in Figure 8. 



Fig. 7. The clothespin, shown in the preceding figure, successfully 
mounted on a piece of broom handle. A softer piece of wood than that 
found in the ordinary broom handle will be easier to work, and it will 
hold thumb tacks better. 


4. Locating the finger muscles. Straighten out your 
index finger and then make it point in various directions. 
While the back of your head is kept motionless, feel your 
forearm and find where the muscle lies that makes the 
finger bend forward. 

A. Where is the muscle that bends your finger, and to 
what are its ends fastened? 

B. Where is the muscle that straightens your index 
finger, and to what are its ends fastened? 

5. Locating other muscles. Where do your muscles lie 
that do the following things: bend your elbow? raise 



Fig. 8. A wooden man. His arms and legs can be set in various positions 
by shifting the thumb'tacks that attach the rubber bands to the body. 
























HYGIENE BY EXPERIMENT 


14 

your arm at the shoulder? bend your head forward? 
raise your thigh while you are sitting? bend your leg at 
the knee? straighten your foot at the ankle? bend your 
toes downward? 

6. Finding out about the arm muscles. By trying out 
on a pole, or a tree limb, find how many times you can 
chin yourself. What pupil in your class can chin himself 
the most times? Who cannot chin himself at all or per¬ 
haps only once? Which pupil in the class has the biggest 
arm in proportion to his body? 

Exercise II. Keeping a Good Posture 

1. Improving your posture. Show on your wooden 
man what muscles must be stretched to make a person 
naturally stand straight, with head erect. 

A. Which, if any, of your own neck muscles need 
strengthening? 

B. What can you do to give yourself the best head and 
neck posture? 

2. Spoiling good posture. What are some of the 
things that you sometimes do in school, on the play¬ 
ground, and around home that tend to give you a bad 
carriage of the body? 

3. Taking your posture angles. The ideal standing 
posture is a nearly straight line for the head and neck, 
upper and lower trunk, thighs, and legs. Stand in your 
usual manner near a straight stick rising straight up from 
the floor. Let the teacher or some member of the class 
note how much, if any, each portion of your body bends 
away from a straight line. Draw a line to represent your 
posture as in Figures 3, 4, and 5. Make a copy of this line 
in your notebook and label it, “My Posture Angles.” 

4. An exercise to improve posture. The posture defect 


MAKING THE BODY STRONG AND STRAIGHT 15 


that you are most liable to have consists in carrying 
the head bent forward too much. A good exercise to help 
correct this is called “bridging.” It is performed as fol¬ 
lows: At home, preferably just after rising from bed, lie 
down on your back, loosely fold your arms on your chest, 
and arch the body as much as possible by supporting it 
on the heels and the back of the head. You will have to 
bend your knees slightly, but not very much. Arch the 
body as fully as possible and allow it to drop back at once. 
How many times in succession can you do this exercise 
of bridging before you have to stop to rest, and how 
many times can you do it after practicing every morning 
for a week? 

5. Your footprints. Soak a piece of cheesecloth or 
other cloth with a half-and-half mixture of water and 
strong glycerine solution of chlorid of iron. When you 
have taken your shoes and stockings off at night, lay on 
the floor or on a smooth board a sheet of unglazed paper 
large enough for you to make two footprints on it. Rub 
the sole of one foot all over with the saturated cloth, in 
order to get a thin coat of the solution spread over the 



Fig. 9. The print at the right is that of a properly shaped foot, while 
the print at the left is that of a foot with badly broken arches. The 
inner prints show two grades of imperfection due to different degrees of 
breakage. Which of these footprints do the prints of your own feet 
most resemble? 


i6 


HYGIENE BY EXPERIMENT 


bottom of your foot. Place the foot on the sheet of un¬ 
glazed paper, throwing the full weight of the body on the 
foot, without any wabbling, and then remove the foot. 
Similarly, take an impression of the sole of the other foot. 
Wash both feet without further delay. Write your name 
on the back of the paper and lay it away to dry. At some 
later class time, the teacher will probably make a display 
of all the footprints brought in by members of the class, 
not giving the names of the owners. The footprints may 
then be examined and compared with the prints shown in 
Figure 9. 

If it is desired to make the footprints black, press the 
paper back down on a piece of cheesecloth moistened with 
a water solution of tannic acid. The moistening of the 
glycerine and the iron chlorid with tannic acid makes a 
real ink. Paste your footprints in your notebook. What 
kind of footprints do you have — good, fair, or poor? 

6 . A good sleeping position. If you are stooped, you 
can improve the way you carry your shoulders, or you 
can help to keep your shoulders more nearly square and 
erect, by the way you lie while asleep. A good posture to 
take for sleeping is to lie on one side of the body and keep 
the under arm behind the trunk instead of in front of it. 
What is your sleeping posture? 


Exercise III. Questions on the Foregoing Exercises 

1. How do you think a muscle gets shorter when it 
contracts? 

2. How do you manage to walk? 

3. Where are the muscles that are most used when you 
are running? 

4. Why is it worth while to be strong? 


MAKING THE BODY STRONG AND STRAIGHT 17 

5. In what two different ways can you fix your wooden 
man so that he holds his head bent forward? 

6. What are two different reasons, therefore, why 
some people may carry their heads with the neck bent 
forward? 

7. What are you going to do to retain or to develop 
a good carriage of your body? 

8. What are you going to refrain from doing so as not 
to spoil the carriage of your body? 

9. Does each of your footprints show two good arches, 
one crosswise back of your toes and the other between this 
arch and your heel? 

10. Why should you try to correct flat-footedness? 

11. If your toes are crowded together too much, how 
can you correct the defect? 

Exercise IV. Questions for Investigation 

1. What is the skeleton? 

2. What is a muscle? 

3. How can you keep a good posture while standing 
or walking? 

4. How can you keep a good posture while sitting? 

5. How may a poor posture be harmful to health? 

6. Why is it particularly important to keep a good 
posture throughout childhood and youth? 

7. Why should exercise not be neglected? 

8. How can flat-footedness be corrected? 

9. Give three rules by which to be governed in taking 


exercise. 


STUDY THREE 


GOOD AIR AND HOW TO BREATHE IT 

One manufacturer builds automobiles to run 10,000 
miles before they should need much fixing. Not all his 
machines run that far, but the fault is not his. Some 
drivers are careless with the machines, and they wear 
them out long before they have run the 10,000 miles that 
they should. 

Most animals live five times as long as it takes them to 
grow up, and a human being grows up in about twenty 
years. How long, then, should a man or a woman live? 
Why do so few people live that long? You are to study 
your own body, the most wonderful of machines, so that 
you may know how to make it last as long as it should. 
Your first step in this study will be to examine your 
breathing. 

Exercise I. Making a Lung Tester 

You will need a spi-rom'-e-ter, or lung tester, to meas¬ 
ure the volume of your breath. One of these can be 
bought; but it is cheaper and much more interesting to 
make one (Fig. 10). For a home-made spirometer you 
need a big bottle — one that will hold a gallon, or about 
that much. Set your bottle on a level table. Take a 
cylinder-shaped water glass and find out how high up 
10 cubic inches of water will fill the glass. Then make a 
scratch or an ink stroke on the outside of the glass at the 
level that marks just 10 cubic inches. 

Now begin to fill your gallon bottle, putting into it 10 
cubic inches of water. Using a sharp file, cut a mark on 
the outside of the bottle at the level of the water now in 
it. Put 10 more cubic inches of water into the bottle and 

18 


GOOD AIR AND HOW TO BREATHE IT 


19 



Fig. 10. Testing the lungs with homemade apparatus. Note the marks 
on the big bottle and the way in which the bottle is held. 


scratch another mark at the new level. Keep this up 
until the bottle is full and you have completed marking 
the side of the bottle. Of course, one such bottle will do 
for the whole class. 

For your study you will also need a dish pan or some 
other big vessel, a rubber tube having an inside diameter 
of about inch and about 2 feet long, and a glass tube 
about 3 inches long stuck into one end of the rubber tube 
for a mouthpiece. There should also be at hand a bottle 
of strong denatured alcohol with a poison label on it, a 
small pitcher of water, and a waste bucket. 







20 


HYGIENE BY EXPERIMENT 


1. What kind of lung tester have you decided to use? 

2. Make a drawing of your lung tester. 

Exercise II. Testing Your Lungs and Studying Breathing 

1. Getting ready to test. Pour water into your lung 
tester until it is clear full. Also fill your dish pan, or other 
vessel, about three fourths full of water. Put your hand 
tightly over the mouth of your bottle and turn it upside 
down, putting its mouth under the water in the other 
vessel. Now put one end of the rubber tube into the 
mouth of the bottle. Some one must hold the big bottle 
so its mouth will be near the bottom of the water in the 
vessel, and he must keep the end of the tube in place. 

2. Taking the test. Before testing the lungs, you must 
destroy the germs on the glass mouthpiece of the rubber 
tube by pouring a few drops of denatured alcohol on it 
and then rinsing it thoroughly with water. You must 
then, while sitting crowded down in a seat, take in the 
biggest breath possible without straightening up. Place 
the mouthpiece of the rubber tube in your mouth and 
exhale into the big bottle all the breath you can without 

' taking more breath into your lungs. The person holding 
the bottle must see that the level of the water in the 
bottle is even with the surface of the water in the vessel 
at the moment when you get through blowing. Then he 
must hold the bottle exactly at this level until he has 
counted the number of cubic inches that show your 
breathing capacity. 

Now pour some clean water on the mouthpiece of the 
rubber tube, some drops of denatured alcohol, and then 
some more water, leaving the tube ready for the next 
pupil to use. The records of all members of the class 
should be placed on a blackboard, for making compari- 


GOOD AIR AND HOW TO BREATHE IT 


21 


sons in the form of a table. What is your breathing ca¬ 
pacity while sitting down humped over? 

3. Making the record. Let a record now be taken of 
yours and the other pupils’ lung capacities when standing 
perfectly erect. Let each pupil in turn stand erect, draw 
all the breath he can, rise on his toes and draw more 
breath if he can, and then quickly take the glass mouth¬ 
piece and exhale into the bottle all the breath he possibly 
can. 

A. What is the breathing capacity of each pupil 
while standing perfectly erect? 

B. In which test, sitting or standing, did you give off 
the larger breath and why? 

Exercise III. Experiments with Breathing 

1. Saying “Ah.” See how many seconds you can 
continue to say “Ah,” using as little breath as possible 
while doing so. Set down the result along with the results 
for the other pupils, both on the blackboard and in your 
notebook. How long can you continue to say “Ah” with 
only one breath? 

2. Breaths per minute. By careful counting, find out 
how many times you take in breath naturally in a minute: 
first, after you have been sitting quietly; and, second, 
after you have been running for a half minute or so. 
Write your answers in the table on the blackboard and 
also in your notebook. How many breaths a minute do 
you take when you have been quiet, and how many 
do you take after exercise? 

3. How you breathe. Let some one in the class 
provide a stopperless bottle that might have held about a 
quart, but with the bottom now knocked out of it. The 
broken end will need to be rubbed with a file to take off 


22 


HYGIENE BY EXPERIMENT 


its sharp edges. A piece of rubber dam, such as a dentist 
uses, 5 or 6 inches square, must now be tied tightly over 
the bottom end of the bottle. 

The teacher, in the presence of the class, will illustrate 
how you get air into and out of your lungs. While holding 
the bottle before the class with one hand, she will press 
the rubber bottom of it upward until it goes an inch or 
more into the bottle. Let a pupil now hold a burning 
match over the mouth of the bottle while the teacher 
takes her hand away from the bottom and then presses 
the bottom upward again, the class meantime watching 
how the flame behaves. Why does the flame go from the 
mouth of the bottle when the bottom is pressed upward, 
and into the bottle when the pressure is withdrawn? 

4. Abdominal breathing. Across the middle of the 
body there is a big, broad, sheet-like muscle called the 
di'a-phragm, fastened all around the lower ribs, and 
separating the upper part of the trunk from the lower 
part. The organs in the lower part of the trunk thrust 
the diaphragm up into the chest so that the muscle is 
usually placed like a bowl upside down. You need to 
find out how you make this muscle work. To do this you 
must stand and place your hands on your abdomen. 
Now drive all the breath you can out of your lungs. 
With the fingers of your hands note what is going on in 
the abdomen and where the muscles are that are doing the 
work. Now take in a good, full breath, keeping the hands 
where they were, and notice where the same muscles, or 
different ones, do the work for taking in breath. The 
kind of breathing you have just been doing is called 
abdominal breathing. In abdominal breathing, where 
are the muscles located that are used when breathing 
in; and where are those located that are used when 
breathing out? 


GOOD AIR AND HOW TO BREATHE IT 


23 


5. Chest breathing and mixed breathing. Try to 

breathe again, this time placing one hand on your chest 
and the other on your abdomen. See if you can breathe 
and yet move only the ribs and not the abdomen. If you 
succeed, you know what is meant by chest breathing. 
Mixed breathing uses both the chest and the abdomen. 
With chest breathing you use some muscles between 
the ribs. Have someone measure your chest when you 
have forced out of your lungs all the air you can and 
again when you have filled them as full of air as possible. 
Place the tapeline around your chest a little below the 
armpits. Write the results in the proper place in the 
table of your measurements in connection with Study 
One. 

A. Where are the muscles that are used in chest 
breathing? 

B. What is mixed breathing, and why is it valuable? 

C. What is the girth of your chest when you have 
filled your lungs as full as possible? 

D. What is the girth of your chest when you have 
emptied your lungs as much as possible? 

E. What is your chest expansion; that is, the difference 
between the two measurements just taken? 

Exercise IV. Experiments with Air 

For the following experiments you will need two wide- 
mouthed bottles, each holding about a pint. Milk bottles 
holding a pint are about the best kind of bottles to use. 
You will also need two short candles, such as are used 
on birthday cakes. Then you must have some clear 
limewater. This may be bought at a drug store, or it 
may be made by pouring a pint or more of rain water 
over a small chunk of fresh quicklime in a vessel, such as 


24 


HYGIENE BY EXPERIMENT 


a quart fruit jar, and letting it stand until the clear lime- 
water can be poured off into a separate bottle. 

1. What a burning candle needs. The air you breathe 
is made up of several kinds of gases, one of which is 
oxygen. Now anything that burns must have oxygen, or 
the flame will go out. 

Fix both of the candles so they will stand up on pieces 
of cardboard about 3 inches square. Light one of the 
candles and then invert one of the bottles over it, letting 
the bottle stand on its mouth until something happens to 
the candle flame. Keep this bottle covered for later use. 
What happened to the candle flame that was under the 
bottle, and why did it happen? 

2. What a living animal needs. Any animal is like a 
burning flame, in that it has to have oxygen to keep it 
from dying. Put a mouse under a small jelly glass. When 
it begins in a few minutes to pant heavily for breath, let 
it out, for it will die if it stays under much longer. Keep 
the air from the mouse’s breath under the jelly glass for 
later use. Why would the mouse die if you kept it under 
the jelly glass very long? 

3. What a candle flame gives off. At the same time 
that the candle flame in the first experiment was using up 
oxygen, it was making another gas called carbon dioxid. 
You can always tell when you have this gas, because it 
turns limewater milky. Take the bottle left over from the 
first experiment and pour into it some clear limewater; 
then shake the bottle so as to mix the air and the water. 
How do you know that air from a burning candle contains 
carbon dioxid? 

4. What a breathing animal gives off. In a similar 
wa*q test the air in the jelly glass under which you kept 
the mouse. How do you know that the air from a 
breathing animal contains carbon dioxid? 


GOOD AIR AND HOW TO BREATHE IT 


25 


5. Carbon dioxid in ordinary air. May it be that ordi¬ 
nary air, such as was put over the burning candle and 
over the mouse, has a lot of carbon dioxid in it? See for 
yourself. Take a clean bottle with fresh air in it and pour 
a little limewater into it. Now shake the bottle and see 
whether the limewater turns milky. How do you know 
that ordinary air has, at most, not more than an ex¬ 
tremely small amount of carbon dioxid in it? 

6. Is there carbon dioxid in your own breath? Blow 
through a glass tube into the bottle that you just used, 
so as to fill it with your breath, the limewater still being 
in it. Now shake the bottle, mixing the limewater and 
the air that came from your lungs. What have you 
learned from mixing your breath with limewater? 

7. Effect of human breath on a flame. Clean both of 
these bottles and.get some fresh air into them. Again fill 
one of them with air from your lungs. When both bottles 
are ready, start the two short candles to burning, and 
then turn both bottles upside down, one over each can¬ 
dle. Under which bottle, the one with fresh air or the one 
with breathed air, does a candle flame go out the quicker, 
and why? 

8. Is there any odor to your breath? You may now 
fill a bottle or a glass fruit jar with your own breath and 
let it stand, carefully covered, until some time when you 
come in fresh from outdoors. Then smell the contents 
of your bottle or jar. If there is a bad odor, it is probably 
due to decayed teeth or diseased tonsils or nostrils. Does 
a bottle standing a while with your own breath in it 
smell bad, and if so, why? 

Exercise V. Questions on the Foregoing Exercises 

1. Of two boys of the same size but of different lung 


26 


HYGIENE BY EXPERIMENT 


capacities, which one do you think could run the farther 
without getting out of breath, if their hearts are equally 
strong? 

2. Why should you sit erect in your seat? 

3. What do you notice about the chests of the finest- 
looking persons you meet? 

4. How do you suppose you can develop a larger chest 
and lungs? 

5. Will you and the other pupils test your lungs once 
a month to see who in your class can make the biggest 
improvement; that is, who can gain the most cubic inches 
of breathing capacity? 

6. How do you get air into your lungs? 

7. How do you get air out of your lungs? 

8. Which kind of breathing — chest, abdominal, or 
mixed — do you think is best for you, and why? 

9. How do you know the air you breathe out is dif¬ 
ferent from that you breath in? 

10. If your breath smells bad, what should you do 
about it? 

Exercise VI. Questions for Investigation 

1. Why does the body need air? 

2. What breathing is best? 

3. What air is good air? 

4. How can you get fresh air to breathe? 

5. What are the lungs? 

6 . What two distinct things do the lungs do for the 
blood? 

7. How can you keep your lungs in good condition? 

8. What good breathing habits should you have? 


STUDY FOUR 


LEARNING ABOUT YOUR BREATHING ORGANS 

I wonder if you can tell seven different uses of the 
nose without having to think long; but you need not try 
to do this just now. The fact is that the nose is a much 
more important organ than most people realize, to say 
nothing about its being such an ornament to the face! 
You are to have a chance in this Study to learn about 
the nose and the throat as well, for you are about to make 
some interesting experiments with air and breathing. 
Both nose and throat play an important part in the 
breathing act, and whether or not you are to have a 
strong body depends very much on the condition of your 
nose and throat. 

Exercise I. Studies of the Nose 

« 

i. The outside of your nose. With clean thumb and 
finger of one hand, bend the nose down and sidewise to 
find the answers to the following questions: 

A. What keeps the nose from flattening down? 

B . Is the partition between the nostrils made of 
gristle, like the breastbone of a spring chicken, or is it 
made of solid bone? 

C. What part of the outer walls of the nose is made 
up only of flesh? 

D. What part is made up of bone and flesh? 

E. Is your nose wide, or narrow, in comparison with 
the widths of the noses of other boys and girls of about 
your age? 

F. Noses are of various shapes, and it really doesn’t 
matter much what shape your nose is, if only the breath¬ 
ing passages in it are well open. But just for the fun of it, 

27 


28 


HYGIENE BY EXPERIMENT 



Fig. ii. Examining the inside of the nose. Notice 
how the girl holds the mirror in relation to the source 
of light. 

you may answer in your notebook this question: Is your 
nose Roman, Grecian, snub, or some other kind? 

2. The inside of your nose. For the second study of 
the nose you need to sit with your face turned away from 
any strong light (Fig. 11). Hold a mirror in front of your 
face so that the mirror will reflect plenty of light up into 
your nostrils and so that you can see the reflection of your 
inner nostrils in the mirror. Use the fingers of your free 
hand to press or pull the end of your nose in ways that 
will let you see well into one nostril at a time. Find and 
write down the answers to the following questions: 

A. Does the partition between the nostrils divide the 
nose into two equal spaces, or is it placed nearer to one 
side than the other? 






LEARNING ABOUT YOUR BREATHING ORGANS 29 

B. In what part of the nostrils do you find the long 
hairs? 

C. Which wall of a nostril, inner or outer, is the more 
regular and smooth? 

D. Where do you find what seem like red pads? 

E. What direction do the nostrils seem to take at their 
upper ends? 


Exercise II. Uses of the Nose 

1. Smelling. Place any agreeable-smelling stuff under 
the nose and breathe in the odor by one strong but steady 
breath. Now breathe in again, but this time bring the 
air in by jerks; that is, sniff the.odor from the substance. 
In which way can you smell the better, by sniffing 
or by taking a steady breath, and why is this so? 

2. Talking. Press with the finger against one side of 
the nose so as to shut off the air from one nostril, and then 
talk out loud. Do this again, but close the other nostril 
instead of the first one. Now close both nostrils and talk 
out loud. In “talking through your nose,” as you say, do 
you really use your nose? 

3. Moistening the breath. Close the nostrils, and then 
through the wide-open mouth breathe in some very dry 
air from over a warm stove, register, radiator, electric 
heater, or burning lamp, taking in a long breath. Now 
close the mouth and breathe in a long breath of the warm, 
dry air through the nostrils. 

A. Which seems to dry out the quicker, the mouth or 
the nose, on taking in a breath of very warm, dry air? 

B. What becomes of the moisture that is lost from the 
mouth or nose? 

C. How is this a protection to the lungs? 

D. Why do you think the nose dries out less readily 
than the mouth on breathing dry air? 


30 


HYGIENE BY EXPERIMENT 




4. Warming the breath. If possible, breathe in some 
very cold air, first through the mouth and then through 
the nostrils, in each case taking a long breath. 

A. Which is less disagreeable to do, to inhale cold air 
through the nostrils, or through the mouth? 

B. Where does the heat come from that serves to make 
the air warmer and more agreeable in the one case than in 
the other? 

5. Protecting the lungs. When you looked up into 
your nostrils you found some hairs at the lower part. 
You also sa*w that the nostrils deeper in are moist. 

A. What effect do hairs and moisture in the nose have 
on inhaled air that is full of dust? 

B. You sometimes see ill-mannered people “picking 
their noses/’ Where does the stuff first come from that 
they get out of their nostrils? 

6. Destroying germs. The moisture that is found on 
the deeper parts of the nostrils contains some substance 
that tends to kill germs. Why is it important to keep the 
inner surface of your nose in a healthy condition? 

7. Giving facial expression. Keep the nose pinched 
shut for about 5 minutes, just to see how it would be if 
one could not breathe through the nose. If you had to go 
with your nose pinched shut all the time, how would this 
affect the shape of your mouth and face? 

8. Uses of the nose. What are seven distinct uses of 
the nose, as shown in the seven studies you have just 
made? 

Exercise III. Taking Care of the Nose 

1. Using a handkerchief. 

A. To clean the nasal surfaces, put a part of the 
handkerchief over the index finger and then gently rub 


LEARNING ABOUT YOUR BREATHING ORGANS 31 

the surface clean. Why should you not ordinarily put a 
bare finger-end into a nostril? 

B. To blow the nose, place part of a handkerchief 
loosely over both nostrils and hold it in position by 
pressing it lightly against the lower side of one nostril 
to prevent the escape of air through it. Now force a lot of 
air through the partly open nostril, without making a 
loud noise. Treat the other nostril in the same way. 
Have you become skillful in blowing your nose properly? 

C. Why should you not blow your nose without using 
a handkerchief? 

2. Washing your nose inside. Some time you will 
need to wash out your nostrils. This is how to do it: 
Take a cupful of warm water and mix into it a teaspoonful 
of common salt (the cup should be one that will not be 
used for another purpose). Close the mouth and hold one 
edge of the cup against the upper lip and the lower edge 
of the nose. Close one nostril with a finger, duck the nose 
into the water, and very gently draw the salt water up 
into the open nostril. Now force the water out again, 
away from the cup. Repeat several times for each nostril. 
What trouble, if any, did you have in washing out your 
nose inside? 

Exercise IV. Studies of the Throat 

1. The throat, or pharynx. This organ lies back of the 
mouth cavity and may be examined by using a mirror as 
was done in studying the nose. In the back part of the 
mouth you will see a nipplelike body, called the uvula, 
hanging down into the entryway to the pharynx , which 
is the hollow body back of the mouth and uvula. 

A. By trying, see how much you can change the 
length of the uvula. How much can you change it? 


32 


HYGIENE BY EXPERIMENT 


B. There are two stretched bands of flesh running up 
from the outer, back parts of the tongue to the roots of 
the uvula. Are they in front of, or behind , the pharynx? 

2. The tonsils. Unless you have had your tonsils cut 
out, you should find two of them, looking naturally like 
two red, unripe mulberries, about the size of the end of a 
little finger, one on each side of the lower, back wall of the 
pharynx. 

A. Have your tonsils been cut out? If not, are they 
of natural size; that is, as big as a ripe mulberry or the 
last joint of your little finger? 

B. White patches on the tonsils show that there are 
many germs in the tonsils and that they are therefore 
diseased. Are your tonsils very, very red and do they 
show white patches? 

3. The hard and the soft palate. Thoroughly clean your 
fingers, and with one of them feel the roof of your mouth, 
called the palate. The front part has bone above it and 
is called the hard palate. The back part is called the soft 
palate and ends finally in the uvula. If the soft palate 
cannot be pressed up very much, it may be because you 
have adenoids in the back part of your nostrils and the 
upper part of your pharynx, into which the nostrils lead. 
If so, the adenoids should be taken out by a physician, 
for if retained they interfere with all of the seven uses of 
the nose. The operation is a slight one and should not be 
expensive. Do you now have adenoids above your soft 
palate? 

4. The Eustachian tubes or throat-ear tubes. Some¬ 
times when you go up on a high building or come down 
from one, you have a sort of ringing in the ear. You may 
also get this ringing in the ear from other causes. When 
you have it, you may usually get rid of it by simply 


LEARNING ABOUT YOUR BREATHING ORGANS 33 

swallowing. This is because the swallowing act opens up 
a tube leading from the pharynx to the middle ear, which 
then lets air into or out of the middle ear, as may be 
needed, — out of it when you go up, and into it when you 
go down. If this Eustachian tube or throat-ear tube has 
grown full of adenoid substance, swallowing will not stop 
the ringing. You should then have this throat-ear tube 
looked after by a physician, for the condition may lead to 
deafness. What causes a ringing in your ears, if you have 
it? 

5. The epiglottis. So far, we have found five openings 
into or from the pharynx. Another one is at its lower 
end, and through it the food passes into the gullet on its 
way to the stomach. But there is still another opening 
near the lower end, through which the air passes on its 
way from the nose and pharynx to the voice box, or 
larynx , on the way to the lungs. Indeed, if you try hard 
enough you can see the lid to this voice box. This lid 
goes shut when you swallow food. Take the handle of a 
tablespoon and press down the rear of your tongue, so 
that you may see the tip of this voice-box lid, or epi¬ 
glottis, as it is called. How much of your epiglottis did 
you succeed in seeing? 

Exercise V. Voice Box, Windpipe, and Lungs 

For these studies there will be needed the lungs, wind¬ 
pipe, and voice box of some quadruped, carefully taken 
out and put in good condition for examination. 

1. The voice box. This part of the general air passage 
may best be studied if it is cut free from the windpipe 
and then split the long way on the side that is opposite 
the place where the lid, or epiglottis, is fastened. Notice 
that there are no vocal cords that look like “fiddle strings” 


34 


HYGIENE BY EXPERIMENT 


across the voice box, but that there is a fold or ridge about 
halfway down on each side. In life these are stretched so 
they make two sharp edges with a very narrow slot be¬ 
tween them. How do you think the animal made a noise 
with this voice box? 

2. The windpipe. Notice that the windpipe is made 
up of incomplete rings of gristle, while the voice box is 
made of plates of gristle. Why should the windpipe be 
made of so much gristle instead of muscle? 

3. The lungs. Get a glass tube several inches long and 
of such a diameter that the tube will just go into the 
windpipe with a little crowding. Insert the tube a little 
way into the windpipe, thoroughly clean the free end of 
the tube, and through it blow a full breath into the 
animal’s lungs. Float the lungs on a dishpan of water, 
both when they are blown up and when they are not. In 
which case do the lungs sink deeper into the water, and 
what keeps them from sinking entirely under the water? 

Exercise VI. Questions on the Foregoing Exercises 

1. What makes the walls of your upper nostrils so red ? 

2. Because you can bleed so much from the nose, what 
does this show about the supply of blood that goes to 
your nostrils? 

3. How do you think the noise is made when some 
one snores? 

4. Why should you try to keep with you a reasonably 
clean handkerchief? 

5. What are the seven different openings from your 
pharynx? 

6. What keeps the food that you swallow from going 
into the windpipe? 

7. What makes you choke sometimes? 


LEARNING ABOUT YOUR BREATHING ORGANS 35 

8. Why is not the windpipe made of a tube of gristle 
instead of rings? 

9. Why are the lungs often called “lights” by butchers? 

10. Why is it that the lungs of children are pink, of 
middle-aged people slate-colored, and of old people living 
in smoky cities, almost black? 

Exercise VII. Questions for Investigation 

1. Why should you breathe through the nose instead 
of the mouth? 

2. How can you keep your nose in good condition? 

3. How can you keep your throat in the best condi¬ 
tion? 

4. What do you suppose happens to the voice box 
when people get hoarse? 

5. What should be done when you get something in 
your windpipe? 

6. How can you keep your lungs from getting slate- 
colored or black? 

7. Why do you have ribs? 

8. How can you exercise your lungs? 


1 


STUDY FIVE 

THE TEETH AND THEIR CARE 

.# 

You have been learning about breathing and the air 
you need. Soon you will take up the study of foods and 
how to become strong and healthy by means of them. 
But before you study foods you should learn some im¬ 
portant facts about the teeth that stand ready to take 
hold of the food when it comes into the mouth. You will 
be able to save yourself money and not a little suffering in 
time to come, if only you make good use of the instruc¬ 
tion to be found in this Study. 

Exercise I. Studying the Teeth 

i. Temporary and permanent teeth. The teeth that 
come in before a child is four years of age are called the 
temporary or baby teeth. Between the ages of seven and 
twelve, these baby teeth are all exchanged for what are 
called permanent or second teeth. But there are twelve 
permanent teeth that come in only once. At about the 
age of six, the first of these permanent teeth come in. 
There are four of them, one on each side of each jaw, just 
behind the hindmost of the baby teeth. A good many 
people do not seem to realize that the big teeth that come 
in at six years are permanent teeth, and never will be 
replaced naturally. At about the age of twelve, four 
more permanent teeth come in, one just behind each of 
these mentioned above. At eighteen years of age or later, 
the four wisdom teeth come in. One of these is at the 
very rear of all other teeth on each side of each jaw. 

By questioning other persons, or by reading Fergu¬ 
son’s A Child's Book of the Teeth , find out and record how 
many temporary teeth anyone may have at the age of 

36 


THE TEETH AND THEIR CARE 


37 



Fig. 12. The boys here have added hydrochloric acid to water contain¬ 
ing a human tooth, and they are watching the bubbles of gas rise as 
the acid slowly eats the tooth. 


four or five years, and how many temporary and per¬ 
manent teeth he may have at six, seven, eight, nine, ten, 
eleven, and twelve years. 

2. Kinds of teeth. By the use of a mirror in the way 
described in the study of your nose (see Figure n), find 
out the groups of different-shaped teeth you have, and 
if possible, the special use of each group. Make a table 
recording the shape and the special use of each of the 
following groups of teeth: 

A. The four front teeth, above and below. 

B. The single teeth on each side of the group of four 
front ones. 

C. The next two teeth behind the single teeth. 

D. The rearmost single teeth or pairs of teeth (three 
pairs in each jaw in adults). 

3. Names of the teeth. At recitation time your 
teacher will give you the names that dentists use in de¬ 
scribing the teeth. After looking the words up in a big 








38 


HYGIENE BY EXPERIMENT 


dictionary, she will also tell you why each group has 
been given its particular name. 

A. Fill out the chart below; on one side write the 
names that the teacher gives you, and on the other side 
set down the ages at which each pair of permanent teeth 
usually come in. 

B. What teeth do you use in taking bites of bread? 

C. What teeth do you use in tearing meat from bones? 

D. What teeth do you use in breaking a stick of candy? 

E. What teeth do you use in grinding food? 

4. The parts of a tooth. Perhaps you or your teacher 
will be able to borrow from a dentist some human teeth 
for study. With a tooth before you, find out and record 
answers to the following questions about the parts of a 
tooth: 



O PERMANENT TEETH G 




Pig. 13. A diagram of the teeth of the upper jaw. Copy this diagram 
in your notebook. Then at one side write the name of each pair of 
teeth, and at the other side write the ages at which each pair appears. 








THE TEETH AND THEIR CARE 


39 


A. What is the crown of a tooth? 

B. What is the neck of a tooth? 



Fig. 14. A diagram of the structural parts of a 
tooth. Make a copy of this diagram in your note¬ 
book and label each structure with the name the 
teacher gives you or that you find out for yourself. 


C. What is the root or fang of a tooth? 

D. What teeth have only one root? 

E. What teeth have two roots? 






















40 


HYGIENE BY EXPERIMENT 


F. What teeth have three roots? 

5. The structure of a tooth. If some member of the class 
will grind a human canine tooth on an emery wheel, 
holding the tooth sidewise and grinding halfway through 
it, the specimen will be useful for study in connection 
with Figure 14. The teacher will give you the names of 
the structural parts. What are these parts? 

6. Decay in your own teeth. Examine all your teeth 
thoroughly for decayed spots by holding a mirror so 
that it will throw light into your mouth, the light coming 
from somewhere behind your head. Which of your teeth, 
if any, have decayed spots? In answering, give the names 
a dentist would use. 

Exercise II. The Care of the Teeth 

1. Testing for acids. Your teacher will perhaps be 
able to provide each member of the class with a small 
piece of blue litmus paper. In the presence of the class, 
she will then put a drop of hydrochloric acid on a piece of 
the paper. Any acid will change the color of litmus 
paper as the hydrochloric acid does. Try a drop of 
vinegar on litmus paper; try lemon juice; try apple juice. 
What change in color does an acid make on litmus paper? 

2. Acid in decayed matter. Press some blue litmus 
paper against a rotten spot in an uncooked piece of fruit 
or vegetable. What does the litmus paper now show you? 

3. Testing your teeth. Take home with you the 
piece of litmus paper which your teacher will give you. 
In the morning, before cleaning the teeth or eating or 
drinking, rub half your piece of litmus paper on the 
surface of a tooth. Scrub the teeth thoroughly with a 
brush and salt water and then rub the second half of the 
litmus paper on the surface of a clean tooth. What have 


THE TEETH AND THEIR CARE 


41 


you learned from applying litmus paper to an unclean 
tooth and to a clean tooth? 

4. Source of acid on teeth. Perhaps you have already 
learned that decay is caused by bacteria. There are many 
kinds of bacteria in a human mouth, especially if it is not 
kept clean. At best there will always be bacteria there, 
and the only way to keep down their number is not to let 
particles of food lodge between the teeth. How did 
acid come to be on your unclean teeth? 

5. Effect of acid on teeth. Place a human tooth in 
half a glass of water and then put in as much as one or 
two teaspoonfuls of hydrochloric acid. You should now 
see bubbles of gas coming from the tooth (Fig. 12). The 
bubbles show that the acid is eating the tooth. Let the 
tooth remain in the glass of acid water for a day. 

A. After a tooth has been in acid for a day or more, 
how does it look and why does it look so? 

B. What difference is there in the rate at which the 
acid has eaten the crown of the tooth (covered with 
enamel) and the root (made up of dentine )? 

Exercse III. Questions on the Foregoing Exercises 

1. What seems to be the particular use of the enamel 
of a tooth? 

2. Why is it not wise to crack nuts with your teeth? 

3. Why is it not a good habit to bite off thread with 
your teeth? 

4. Just how does a tooth come to decay? 

5. Why should you clean your teeth after every meal? 

6. Why is it more important to clean your teeth just 
before going to bed than at any other time? 

7. Do you have a toothbrush? 

8. How often have you been cleaning your teeth? 


42 


HYGIENE BY EXPERIMENT 


9. What are two very different reasons why you 
should keep your teeth clean? 

* Exercise IV. Questions for Investigation 

1. Why is it very important that you take good care 
of your teeth? 

2. How often should you visit a dentist? 

3. Why is it the better way to have a cavity in a tooth 
filled by a dentist before the cavity gets large? 

4. How much stronger is a natural tooth than a 
false one? 

5. Why is it just as important to take good care of the 
first teeth as of the second teeth? 

6. What sometimes makes permanent teeth come in 
crooked? 

7. What should be done with crowded or uneven 
teeth? 

8. What are some diseases that may be caused by 
decayed teeth ? 

9. What is a good kind of toothbrush? 

10. What different motions should you go through in 
brushing your teeth? 

11. Why is it particularly important to brush your 
teeth up and down as well as crosswise? 

12. What are some habits that will help you to have 
sound and good-looking teeth? 


STUDY SIX 

WHAT AND HOW TO EAT AND DRINK 

No doubt you have seen some boy you know walking 
slowly about his home yard. He could not run or play, 
and was so weak that he had to sit down often to rest. 
This was because he had been sick, and for a good many 
days had not been able to eat. Now he was beginning 
to eat a little and was getting back his strength. The 
health and strength of all of us depend so much on our 
foods that it will be quite worth while to make some 
study of what and how we eat and drink. 

Exercise I. Examining Your Mouth 

With a strong light coming from behind your head, 
hold a mirror in front of your wide-open mouth so as to 
throw a lot of light into it. Now examine the mouth to 
find each of the parts shown in Figure 15. At the right of 
the chart set down the names of the parts, as your 
teacher may give them to you, or as you may find them 
in some other book. 

Exercise II. Some Uses of the Mouth 

1. Breathing. Run hard until you feel that you simply 
cannot get enough air by breathing through your nose 
alone. How do you manage to get enough breath into 
your lungs when you are running very rapidly? 

2. Speaking. Practice giving the sounds of the capi¬ 
talized letters only in the following syllables: A, Be, 
CHew, De, E, eF, Go, He, I, Jay, Kay, Low, May, Nay, 
iNG, O, Oil, OUt, Pea, Row, See, Tea, THe, THigh, 
U, Ve, We, Ye, Ze, ZHe. 

A. Which letters of the alphabet represent free, open 
voice sounds or vowel sounds? 


43 


44 


HYGIENE BY EXPERIMENT 


B. Which represent merely whispered or aspirate 
sounds? 



Fig. 15. This diagram indicates the different struc¬ 
tures that can be seen in the mouth. With the aid 
of a mirror, examine these structures in your own 
mouth. Then copy the diagram in your notebook 
and write at the side of the diagram the names 
of the parts. 
































































































WHAT AND HOW TO EAT AND DRINK 


45 


C. Which represent obstructed throat sounds or 
subvocal sounds? 

3. Swallowing. When you have a chance, watch a 
chicken while it is drinking water. 

A. Why does a chicken raise its bill every time it 
swallows water? 

B. Why do you not have to raise your mouth as a 
chicken does, to drink water yourself? 

4. Moistening food. Take a good big bite of cracker, 
crush it rapidly, and then try to swallow it at once. What 
have you learned about the use of the mouth in swallow¬ 
ing dry matter? 

5. Aiding chewing. Eat a raw apple or turnip, or 
recall your eating one of them. For what purpose do you 
use your teeth when you eat such foods as hard fruits? 

6. Aiding digestion. Put a teaspoon ful of raw oatmeal 
into one glass of water, and put a teaspoonful of sugar 
into another glass of water. Let both glasses stand for a 
minute or two, stirring the contents several times. Then 
take two funnels, each emptying into a milk bottle or 
other glass vessel, put a filter paper or any thin, un¬ 
glazed paper down in each funnel so you can separately 
strain the contents of the glasses you have just been 
stirring. Meantime, put a spoonful of raw oatmeal into 
your mouth and keep chewing it until it changes its 
taste slightly. 

A. Which dissolves in the water, sugar or oatmeal? 

B. Which of the two, do you think, might be carried 
through the walls of the food canal so that it could get 
into the blood to be taken around over the body? 

C. What did the saliva in your mouth do with a part 
of the starch in the oatmeal, as you judge from the new 
taste you got when chewing the oatmeal? 


4 6 


HYGIENE BY EXPERIMENT 


D. Why is it necessary that this change be made in 
starchy foods? 

E. What is digestion? 

7. The kinds of food saliva digests. Take a teaspoon¬ 
ful of clean, boiled wheat grains and chew them until a 
small mass of “wheat gum” remains. The saliva, or 
liquid of the mouth, dissolves the starch in the wheat 
grains and leaves a substance called gluten. This gluten 
belongs to a class of foods known as pro'te-in foods. These 
will not digest or dissolve in the mouth, and they must 
go on to the stomach or small intestine to be digested. 
Neither will butter or fat of any kind be digested in the 
mouth. What is the only kind of food the saliva digests? 

Exercise III. The Hygiene of Eating 

1. How to chew. At lunch time take a sandwich con¬ 
taining meat, egg, salmon, or peanut butter, and cut it 
into two exactly equal parts. Eat half of it slowly, chew¬ 
ing every bit until it is like thin soup. Then eat the other 
half very rapidly and with little chewing. At the same 
meal, or a later one, eat the first half of a sandwich 
rapidly and the second half slowly. In which case, 
eating slowly or eating rapidly, do you get the greater 
satisfaction out of half a sandwich? 

2. Advantage of thorough chewing. If you care to 
make a meal of sandwiches alone, it will be worth your 
while to try another experiment with them. With 
enough equal-sized sandwiches before you to serve as a 
meal, eat them as rapidly and with as little chewing as 
possible, taking note of how many it takes to satisfy 
your hunger. At a later, corresponding meal, do the 
same thing, only this time eat slowly and chew very 
thoroughly. Which meal requires the fewer sandwiches, 


WHAT AND HOW TO EAT AND DRINK 47 

the one at which you chew thoroughly or the one at 
which you chew little? 

3. Are fried foods healthful? Think of the time you 
may have eaten fried doughnuts and other fried foods, 
and then think of a time when you ate something else. 
What does your personal experience tell you about the 
healthfulness or unhealthfulness of eating much fried 
food? 

4. How to drink milk. At some meal take a glass of 
milk and pour half of it into another glass. Drink one- 
half very rapidly, and then slowly sip the other half. At 
a later meal sip slowly the first half and drink rapidly the 
other half. Which is the way to drink milk to get the 
full benefit of it? 

5. How much water to drink. Try drinking a glass of 
water before breakfast. Also drink plenty of water at 
meal times, but always when the mouth is free from other 
food. Do this for at least a week, drinking six or seven 
glasses of water a day. Do you find that drinking plenty 
of water makes you feel better and healthier? 

6. Effect of cheerfulness. Think over the times you 
have eaten meals when something has made you cry or 
feel bad. Think of other times when you have been 
happy at mealtimes. In which case did the saliva flow 
the more freely, when you were happy or when you 
were sad? 

7. Vitamins. If a farmer feeds his cattle on corn alone, 
they will not fatten well and will not keep in good health. 
This is why you. see the tall silos beside the barns of good 
farmers. In these the farmer keeps green feed for winter. 
This silage gives to the cattle, among other things, sub¬ 
stances called vitamins. These vitamins, which are 
found most plentifully in fruit, leafy vegetables, and 


48 


HYGIENE BY EXPERIMENT 


milk, are necessary to the proper growth not only of 
cattle but of boys and girls as well. Do you have vitamin 
foods as a part of your daily diet? 

8. How much meat to eat. Many persons eat too much 
meat. When they do this, a good part of the meat is not 
digested but goes down to the large intestine, where it 
only feeds germs. These germs make poisons that some¬ 
times affect the whole body. Is the meat you eat only 
about one-seventh of all the food you eat, if the food 
were all dried and weighed? 

9. Constipation. One of the great causes of many 
ailments lies in the neglect of people to empty the bowels 
at least once a day. Are you very certain that you empty 
your bowels at least once a day, preferably in the morn¬ 
ing? 

10. Your proper weight. Turn to your table of meas¬ 
urements in Study One. If you find that your weight is 
much less or much more, than the standard for you, 
what can you do to make your weight what it should be? 

11. Good table manners. Talk over the subject of 
good table manners with your teacher and with other 
members of your class. Now play that you are eating to¬ 
gether or, better, have a real lunch together. You might 
choose up sides and then see which side, as a whole, is 
the better behaved at meal times, the teacher being the 
judge. Have you learned correct table manners? 

12. A paper drinking cup. Make a drinking cup from 
the pattern shown on the opposite page. Use any strong, 
clear, glazed paper about 8 inches square. The teacher 
will explain, if you do not quite understand just how to 
do it. 


WHAT AND HOW TO EAT AND DRINK 49 

Exercise IV. Questions on the Foregoing Exercises 

1. Which has the more parts to be seen in it, the 
mouth or the nose? 

2. What are the six different uses of the mouth? 

3. Which has the more uses, the mouth or the nose? 

4. What is one way to tell starchy food from protein 
food or fatty food? 



Fig. 16. The method of folding a square piece of paper to form a sanitary 
drinking cup. Crease paper diagonally, placing corner A exactly on 
corner B, as in (1) and (2). Place corner C exactly on the point D, 
making pocket as in (3); fold corner A into pocket thus formed, as in (4). 
Reverse the folded paper and carry out foldings on other side, completing 
the cup, as in (5). 


5. How can you get the most good out of every bite 
you eat? 

6. What less expensive foods could you substitute for 
some of the foods you eat now, and yet be just as well 
fed, or even better fed? 

7. If you have ever had the heartburn, which is really 
a burning sensation in the stomach, what do you think 
brought it on? 














50 


HYGIENE BY EXPERIMENT 


8. Why do you think you ought to have a good deal 
of water at meal times? 



Fig. 17. Copy in your notebook this diagram of 
the organs of digestion. Then write at one side 
the names of the different organs and set down 
at the other side their uses. 



























WHAT AND HOW TO EAT AND DRINK 


51 


9. What are two reasons why you should not wash food 
down or gulp it quickly. 

10. What foods have you found to be harmful to 
yourself? 

11. What foods have you found to be harmless? 

12. What are ten rules for good manners at meals? 

Exercise V. Questions for Investigation 

1. At one side of the chart, Figure 17, write the names 
of the digestive organs, and at the other side write a 
brief statement of the chief use of each organ, as you 
learn these uses from other books. 

2. How can you keep your digestive organs in good 
working order? 

3. Why is milk one of the best of foods? 

4. What are the three main kinds of foods, and what 
does each of these do for you? 

5. Why should you learn to eat many kinds of foods? 

6. What are vitamins? 

7. Aside from the price, what determines the value of 
a pound of food? 

8. Give at least three reasons why most foods should 
be well cooked. 

g. Make a list of hygienic rules for eating and drinking. 


STUDY SEVEN 

TEA, COFFEE, ALCOHOL, AND TOBACCO 

There are many things that are good to eat or to 
drink. But there are other things that are not so good, 
or that are even harmful. Most of us will leave off eating 
particular foods that we find hard to digest or that we 
know will harm us. But many of us keep on drinking 
tea and coffee in spite of the fact that they are harmful, 
because their bad effects do not show themselves quickly. 
Some men, too, who should know better, continue to use 
tobacco and stimulants. It will be well for us to find 
out just what is the harmfulness of some of the sub¬ 
stances that people habitually use. 

Exercise I. Tea and Coffee 

i. Finding a harmful stuff in tea and coffee. If your 

school does not have a small scale, make a pair of 



Fig. 18. Three of these bottles are filled with strained green tea, three 
with strained black tea, and three with strained coffee—each kind of 
tea and the coffee being made in three different ways. Some sulfate of 
copper dissolved in water has been added to the contents of each bottle. 
The deposits in the bottles show the relative amounts of tannin in the 
different beverages. 


52 








TEA , COFFEE , ALCOHOL, AND TOBACCO 


53 


balances, using a ruler as a beam. Weigh out three 
samples of black tea, three of green tea, and three of 
freshly ground coffee, each equal to a dime in weight. 



Fig. 19. Copy this diagram in your notebook, label each test tube, 
and indicate the tannin content for each of the beverages as variously 
prepared. 


Distribute these samples in nine test tubes or in small 
and uniform wide-mouthed bottles. Nearly fill one of 
the test tubes or bottles in each of the three sets with 
cool or cold water, fill the second in each set with water 
that has just been boiling, and put boiling water into the 
third in each set; keep the water boiling in the last set 
for 3 minutes. Label each glass or bottle so that you 
can tell which is which. 

You need next to strain off the leaves and grounds. 
To do this, take a tin cup and pour into it the contents 
of your first tube or bottle. Now strain the liquid 











































54 


HYGIENE BY EXPERIMENT 


through a cloth back into the bottle from which it came. 
Do likewise with the remaining bottles. If the liquids 
in all the bottles are not now at the same level, equalize 
them by pouring a little of the liquid out of the bottles 
that are fullest 

You are now ready to find out wfhat the water dis¬ 
solved from the tea and coffee. For this you need a 
strong solution of copper sulfate in water. Pour one tea¬ 
spoonful of the solution into each of the nine glasses. 
A fleecy substance is formed in the glasses. Allow your 
nine glasses to stand for an hour. Then, from the outside, 
measure with a ruler the heights of the settlings in your 
samples of tea and coffee, and lay off and darken the 
respective heights at the bottoms of the drawings of the 
nine test tubes in the chart, Figure 19. 

2. The nature of tannin. The fleecy substance which 
settled to the bottom of each of the glasses is called 
copper tannate , and since this compound was formed the 
tea and coffee must have contained a substance called 
tannin. Now this tannin is like ordinary alum in its 
effect on the linings of the mouth and stomach. Put a 
little piece of alum in your mouth and note its puckering 
effect. Why might tea and coffee do harm to the linings 
of the stomach and intestines? 

3. The stimulant in tea and coffee. But people do not 
drink tea and coffee for the tannin there is in it. There 
is another substance which is called the-ine in tea and 
caffeine in coffee, that makes people want these drinks 
regularly. Caffeine and theine are exactly the same, and 
both substances may correctly be called “caffeine.” 
Caffeine does not pucker the walls of the food canal, but 
it excites the nerves and makes one wider awake for a 
while. This is why it is called a stimulant. It makes a 


TEA, COFFEE, ALCOHOL, AND TOBACCO 


55 


great many people nervous and is often a cause of head¬ 
ache. It is particularly injurious to growing boys and 
girls. 

Now this caffeine is present in tea and coffee in about 
the same proportion as the tannin, but the amount of 
caffeine given up is about the same whether hot or boiling 
water is used. What then, would be the best way to 
make tea or coffee in order to get the smallest amount of 
tannin? 


Exercise II. Alcohol 

1. The appearance of alcohol. Examine some dena- 
natured grain alcohol and find out what the word de¬ 
natured means when applied to alcohol. What have you 
learned directly from seeing and smelling grain alcohol, 
and what is put into grain alcohol to denature it? 

2. The burning of alcohol. Pour several drops of al¬ 
cohol into a saucer and set fire to the alcohol. In what 
three ways does an alcohol flame differ from the flame 
of a burning match? 

3. Alcohol as a solvent. Pour some alcohol on a frag¬ 
ment of varnished wood, some on a bit of rosin in a small 
bottle, and some on a few drops of oil in a small bottle. 
What happens when alcohol is poured on varnish, rosin, 
or oil? 

4. Alcohol and cell material. The living cells that 
compose the human body are made of a material that is 
a great deal like the raw white of an egg. Pour alcohol 
on some raw white of egg. What does alcohol do to it? 

5. Alcohol and living flesh. One can see how alcohol 
affects flesh by pouring alcohol on a small piece of 
fresh, lean meat. What effect does alcohol have on lean 
meat? 


56 


HYGIENE BY EXPERIMENT 


6. Testing for alcohol. Take about a teaspoonful of 
alcohol, pour it into a small bottle, and add 5 more tea¬ 
spoonfuls of water. Now tie a wire to a little piece of 
sheet copper and heat the copper red hot. Continue 
heating until the copper, on cooling, will appear dark. 
While the blackened copper is still very hot, thrust it 
into the solution of alcohol. Remove the wire and see 
what has happened to it. Heat the copper again, and 
this time thrust it into pure water. Try this test on 
Peruna, Tanlac, or Lydia E. Pinkham’s Vegetable 
Compound. How can you tell whether a liquid has as 
much as fifteen or twenty per cent of alcohol in it? 

7. Another test for alcohol. Take the diluted alcohol 
used in the last experiment and bring it to a boil. Now 
hold a lighted match to the mouth of the bottle. In the 
same way, try samples of any of the patent medicines 
named above. 

A. What is a second test for the presence of alcohol 
in a liquid? 

B. What have you learned about some patent medi¬ 
cines? 

Exercise III. Tobacco 

1. Tobacco in water. Put about an inch of water into a 
small bottle. Then drop a piece of tobacco, about as big 
as a garden pea, into the bottle. 

A. How do you know that water dissolves something 
out of the tobacco? 

B. What is one of the substances the water dissolves? 
Look up the definition of nicotine in the big dictionary. 

2. Tobacco in the white of an egg. Put another bit of 
tobacco on some raw white of egg. Recall that the cells 
of which the body is composed are made of a substance 
that is much like the raw white of egg. 


TEA, COFFEE, ALCOHOL, AND TOBACCO 


57 


A. Does f he raw white of egg take up nicotine? 

B. Would the cells of the body be likely to take up 
nicotine? 

3. Effect of nicotine on small animals. Put a drop of 
tobacco solution on a fly or other insect that is a pest. 
What happens to the insect? 

4. Effect of nicotine on skin. Put two or three drops of 
tobacco solution on your little finger where it is white 
and clean. How does the liquid change the color of your 
finger? 

5. Vaporization of nicotine. Take a bit of tobacco no 
larger than a pea and place it on a thin metal plate sup¬ 
ported over a flame. Note the odor. How do you know 
that nicotine vaporizes when heated? 

6. The fumes of nicotine. Stick a piece of tobacco as 
big as a garden pea on the end of a wire or a hatpin and 
thrust it into a flame. Is the resulting odor different from 
the odor that you noticed when you heated a bit of 
tobacco? 

Exercise IV. Questions on the Foregoing Exercises 

1. What use do barbers sometimes make of alum? 

2. Why is baking powder that has alum in it thought 
not to be healthful? 

3. Which has the most tannin in it, and which has the 
least, black tea, green tea, or coffee? 

4. What is alcohol? 

5. Why should you look carefully at a label on a 
patent medicine bottle before you even consider taking 
any of the medicine? 

6. What is lemon extract? Witch hazel extract? 

7. Why do housewives sometimes sprinkle a solution 
of tobacco on house plants? 


58 


HYGIENE BY EXPERIMENT 


Exercise V. Questions for Investigation 

1. Why are boys and girls better off if they do not 
drink tea or coffee? 

2. What two digestive organs are most harmed by the 
use of alcohol? 

3. How does tobacco affect the heart? 

4. How does the pulse beat of a smoker differ from that 
of a non-smoker? 

5. How does tobacco affect the digestive organs? 

6. How does tobacco affect the nervous system? 

7. How does tobacco affect the work of pupils in 
school ? 

8. Why do managers of football teams not permit 
their men to use tobacco? 

9. What are some habits that one should not form? 


i 


STUDY EIGHT 

THE BLOOD AND ITS CIRCULATION 


Your study of foods and drinks no doubt has brought 
to your mind several questions. How does the food get 
to the parts of your body that need it? What happens to 
the food when it gets to those parts, and what becomes 
of the waste material that is replaced? These are some 
of the things you will now have a chance to find out 
about. 

Exercise I. What Blood Is Like 

i. Blood seen through a microscope. If the school has 
no microscope, your teacher or one of your classmates 
may be able to borrow one for a day, perhaps, from a 



Fig. 20. To examine human blood, a drop of it is placed 
on a little piece of glass. This glass is covered with 
another glass that is very thin. The prepared “slide” is 
then placed on the stage of a compound microscope. 

59 




















6o 


HYGIENE BY EXPERIMENT 


physician. The teacher will then place a tiny drop of 
fresh human blood on a slide and cover it with a cover 
glass. Set the microscope so that it will magnify a 


Fig. 21. Corpuscles found in human blood, highly 
magnified. A red corpuscle is shaped about like a 
circular piece of mint candy, thinned at the center 
to leave a heavy rim all around. The white cor¬ 
puscles are not regular in shape. 



hundred times. As you look at the blood mounting 
through the microscope, you should now see numerous 
tiny, pale, yellowish-red bodies floating in a liquid. The 
liquid is called plasma and it carries food and waste. 
The reddish bodies are called red corpuscles of the blood. 
They serve to carry around to the different parts of the 
body a gas called oxygen , which the body needs for its 
work. 







THE BLOOD AND ITS CIRCULATION 


6l 


2. Examining clotted blood. Let somebody bring to 
class a small bottle of fresh blood from a chicken. Then 
allow the blood to stand until it clots. 

A. What do you think the most of the red mass of 
clotted blood is made of? 

B. The liquid that gathers around the outside of the 
clot is a little different from plasma because the plasma 
lost a small part of itself in helping to make the clot. 
The liquid is now called serum. What does the serum 
look like? 

Exercise II. How the Blood Circulates 

1. Studying pulse waves. Take off the bulb and tube 
from an atomizer, a little instrument that can be gotten 
at a drug store. The tube should be at least a foot 
long. Fill the bulb with water, and then, while squeez¬ 
ing the bulb with one hand, hold the rubber tube lightly 
between the thumb and forefinger of the other hand. 
Notice the wave of water that runs along the tube. 
Squeeze the bulb several times, first quickly and then 
slowly. What is the difference in the two kinds of out¬ 
going waves that run along the tube? 

2. Counting your pulse. Place the ends of the first and 
second fingers of your right hand on the inside of your 
left wrist, an nch or more above the root of the thumb. 
Feel around until you find a good pulse or wave of 
blood. Count the pulse waves per minute in each of 
the following cases: 

A. When you have been sitting quietly for a while. 

B. After you have been running hard for a couple of 
minutes. 

3. Relation of heartbeat to pulse beat. Place your 
finger tips at the lower end of your breastbone and then 


62 


HYGIENE BY EXPERIMENT 


move them an inch or more to the left until, between the 
forward ends of the fifth and sixth ribs, you can feel the 
lower point of the heart beating against the chest wall. 
The rest of your heart is above and to the right of this 
beating point. Your stomach is just below this point. 

Press the finger ends of one hand against the beating 
spot of the heart, and press the finger ends of the other 
hand against the big pulse in the neck by the side of 
the voice box. 

A. If the pulse beats in the neck and over the heart 
do not come at exactly the same time, which one of them 
is a bit ahead of the other? 

B. How do you account for this difference in time of 
these two pulses? 

4. Relation of age to pulse. What is the pulse beat 
frequency per minute of people of about the following 
ages, when they are sitting quietly: One year or less? 
ten years? thirty years? sixty years? 

5. Sounds from a heartbeat. Listen to the beating of 
somebody else’s heart by placing your ear against the 
chest about an inch to the left of the very center of the 
breastbone. 

A. When listening to the beating of a heart, do you 
hear two different sounds, one right after the other? 

B. Which sound is short and sharp, and which sound 

is long and dull? , 

Exercise III. Questions on the Foregoing Exercises 

1. What makes the blood soon stop flowing from a 
slight wound? 

2. How can you tell if the blood from a wound is 
coming from an artery , a vessel carrying blood from the 
heart? 


THE BLOOD AND ITS CIRCULATION 


63 


3. From a vein , a vessel carrying blood to the heart? 

4. Since your blood carries oxygen around to your 
muscles to set energy free for motion, why does your 
heart beat oftener when you are running? 

5. Why do you have to open your mouth to breathe 
while running very hard? 

6. Why cannot people with weak hearts run long at 
a time or very fast? . 

7. What effect does age have on the rate of a person’s 
heartbeat? 

Exercise IV. Questions for Investigation 

1. What is blood for? 

2. What is the heart for? 

3. What are the arteries for? 

4. What are the veins for? 

5. How does the blood get over to the arteries from 
the veins? 

6. How does the food in the blood get out among the 
body cells? 

7. Why should you not exercise your heart too much, 
as in hard games and long-distance running? 

8. How can you stop the bleeding from a wound? 

9. How can you stop nose bleeding? 

10. What habits should you form to benefit the heart 
and to keep a good blood circulation? 


STUDY NINE 

CARING FOR THE SKIN 

We most naturally think of the skin as the covering of 
the body. The skin, together with the hair and nails and 
eyes is all that we see of one another; and there is some 
truth in the old saying, “Beauty is only skin-deep.” 
But the skin has several uses besides serving as a body 
covering. In this study we shall consider what its several 
uses are. 

Exercise I. Studies of the Skin 

1. The skin magnified. Use a strong simple magnify¬ 
ing glass to examine the skin of your hand. Notice how 
scaly it looks. When the hand is sweaty, scrape some of 
the scurf off the skin. What is this scurf, and why can 
you never free your skin of it entirely? 

2. Why skin smells bad. Recall the smell of decaying 
flesh, as of a dead cat, rat, or other decomposing animal. 

A. Does human skin smell bad sometimes? 

B. Why does clothing, especially that worn near the 
skin, sooner or later get to smelling bad? 

C. What is better than perfume to kill body odors? 

3. Washing and bathing. Some time when your hands' 
are not very clean, wash them as well as you can in clear 
water. Smell the hands to see if there is any odor. Now 
wash them again, using unscented soap and warm water. 

A. Why do the hands smell better after they have 
been washed with plain soap and water? 

B. What is really the reason why you should bathe? 

C. How often ought you to bathe? 

4. The effect of soap on oil. 

A. Put several drops of oil on some water in a small 
bottle and then shake the bottle. Let the bottle stand 

64 


CARING FOR THE SKIN 


65 



Fig. 22. These children are allowing their skins to get training that 
will help their bodies to guard against colds. Of course, care must be 
taken to avoid getting chilled while enjoying such a bath on the lawn. 


for a while and note what the oil does. Into a similar 
bottle put some very soapy water and add several drops 
of oil. Shake the bottle and let it stand for a short while. 
What happens to the oil in each bottle? 

B. Poison ivy is a plant whose leaves and stems give 
off a volatile oil that irritates the skin. Why should one 
immediately wash any parts of his body that may have 
come in contact with the ivy, using plenty of soap? 

Exercise II. Why the Skin Needs Ventilation 

1. Seeing sweat pores. Look through a magnifying 
glass at the skin in the palm of your hand. Notice the 
little ridges. Now look very sharply for tiny depressions 
along the tops of the ridges. These are the outlets of the 
sweat pores of the skin. A tiny droplet of sweat may be 
seen at the outlet of each pore. Similar depressions 









66 


HYGIENE BY EXPERIMENT 


occur all over the skin, but they are not so easily seen 
elsewhere. In your notebook make a large-scale 
drawing of one of the tiny ridges on the palm of your 
hand, showing the depressions where the sweat comes out. 

2. Insensible perspiration. On a day when the tem¬ 
perature is below 50 degrees Fahrenheit, or in a place 
where you can get that temperature, put your hand into 
a Mason fruit jar, in which you have first placed a 
thermometer. Do not allow the skin to touch either the 
sides of the jar or the thermometer. Stop up the unoccu¬ 
pied part of the jar with a handkerchief. When you have 
held your hand in the jar for perhaps a minute, note that 
the temperature on the inside of the jar is still only about 
ten degrees warmer than that on the outside. After 
five or ten minutes note the appearance of the inner sur¬ 
face of the jar. What have you learned from this ex¬ 
periment? 

3. Effect of volatile liquids on the skin. Pour a few 
drops of ether, alcohol, or gasoline, on the palm of your 
hand. Pay no attention to the odor, but notice only 
whether the hand feels cold as the liquid quickly evapo¬ 
rates from the surface of the skin. 

A. When does the spot where the liquid was poured 
cease to feel cold? 

B. Why does not the liquid itself feel so cold when 
you put your finger into it? 

4. Effect of vaporization on temperature. Insert the 
lower end of a dairy thermometer into a small bottle of 
ether, alcohol, or gasoline, and note the temperature of 
the liquid. Now remove the thermometer and watch 
the movement of the mercury column as the liquid 
evaporates. Watch the mercury for a minute or more 
after the liquid has evaporated entirely. 


CARING FOR THE SKIN 


67 


A. As the liquid was evaporating from the bulb of the 
thermometer, what was the effect on the temperature of 
the thermometer? 

B. What is the effect of rapid evaporation on tempera¬ 
ture? 

C. Why did the liquid in Experiment 3 make your 
hand so cold? 

D. Since you perspire when you are very warm, what 
do you think is the main reason for your perspiring at all? 

5. Effect of air in motion on vaporization. In a moder¬ 
ately warm room put two or three drops of water in each 
of tw r o saucers. Keep the air in motion over one saucer 
by fanning. Notice how many minutes it takes for the 
water to evaporate from each saucer. What seems to be 
the effect of moving air on evaporation? 

6. The effect of motionless air on skin temperature. 
Put on a raincoat that is much too large, keeping it away 
from the body with a square wooden frame that rests on 
the shoulders, as in Figure 23. Take the temperature of 
the inside air. Now let some one take hold of the coat 
at the frame, giving the coat a swinging motion until the 
air is well stirred inside. Take the temperature once more. 

A. What was the thermometer reading at the be¬ 
ginning of the experiment? at the end of the standing 
still? after the air had been set in motion? 

B. Did you feel much cooler when the coat was 
swinging than when it hung still? 

C. Recalling the experiment with the drops of water 
on the saucers, what do you think made you feel dif¬ 
ferent when the air was stirred on the inside of the coat? 

D. What is a very important reason for ventilating a 
living room? 

7. The skin a source of odors. Let the person who is 


68 


HYGIENE BY EXPERIMENT 


working with you, in taking the raincoat off from you, 
be sure to unbutton it at the top only, and slowly lift the 
coat up over your head, so as to give you a chance to 
note the odor of the air that has been inside the coat. 

A. What makes the air of a crowded room smell bad? 

B. For what other reason than cooling the body when 
warm should a living room be kept well ventilated? 

C. If everybody were to keep reasonably clean, would 



Fig. 23. Why is it that the air in a room that is occupied 
needs to be kept in motion? The little girl shown here 
is submitting to an experiment that will give the answer. 


















CARING FOR THE SKIN 69 

it be as necessary as it now is to ventilate the average 
living room? 

Exercise III. Questions on the Foregoing Exercises 

1. State two important uses of the skin as shown by 
the above experiments. 

2. Since it is not quite true, as some people have said, 
that we sweat to throw off waste matter, what shall we 
say is the important reason we perspire? 

3. A Nebraska farmer and his hired hands take shower 
baths and put on clean overalls just after the day’s work 
is over and before going in to supper. What do you 
think of this way of doing; namely, cleaning up before 
the evening meal? 

4. What are two important reasons why a living room 
needs to be ventilated? 

Exercise IV. Questions for Investigation 

1. What are the parts of the skin? 

2. What four different kinds of sensation does one get 
from the skin? 

3. How does the skin help to regulate the body tem¬ 
perature? 

4. Why should you bathe? 

5. Which is better, to use perfumes to hide bad odors, 
or to take a bath and remove the source of the odors? 

6. What are some good habits to form in caring for 
the skin? 


STUDY TEN 

TAKING CARE OF THE FINGER NAILS, HAIR, AND SCALP 

Why do you have finger nails and hair? If you did not 
have them, you would at least not have to bother to get 
them trimmed. What a relief it would be not to have to 
comb your hair when you get up in the morning! Still, 
baldheaded people do not seem to enjoy being bald- 
headed. There must be some use for hair, after all, 
and for nails, too. What can these uses be? 

Exercise I. Studies of the Finger Nails 

1. Facts about the nails. Make a study of your finger 
nails to find out answers to the following questions: 

A. How do your nails differ from your skin? 

B. What two reasons can you give for believing that 
nails steadily grow out from the roots? 

C. Does a nail get thicker the farther it grows out 
from the root? Find out by pressing with a dull pencil 
point at various places on the nail. 

D. How do the three parts of your nails differ in 
color — the base or part rising from the root, the central 
part or body, and the outer part or free margin? 

E. Since the nail itself is not pink as seen at the mar¬ 
gin, why do you think the central part looks pink? 

F. Since the margin of the nail itself never really gets 
black, what makes it look black sometimes? 

G. Why could you not get along very well without 
finger nails? 

2. Caring for the roots of nails. Sometimes you find 
that the skin at the root of a nail hangs to the base of the 
nail. It may even hang on so long as to be partly pulled 
away from the rest of the skin as the nail continues to 
grow. This makes the nail look very ragged. 

70 


CARE OF FINGER NAILS, HAIR, AND SCALP 71 



Fig. 24. At the left is shown the hand of a nail biter, and at the right 
is shown the hand of a person who has never bitten the nails. Which 
kind of hand should you prefer? A nail clip that may be bought for a 
dime or a quarter will save fingers, teeth, and self-respect. 


A. What can you do to keep the skin from clinging to 
a nail at the base? 

B. How can this best be done without injury to skin 
or nail? 

C. What have you found to be the best thing to use 
in trimming your nails? 

D. After studying Figure 24, why do you think you 
should avoid the habit of biting your nails? 

Exercise II. Studies of the Hair and Scalp 

1. Examining a hair. Secure a hair freshly pulled from 
your head and examine it with a microscope or a strong 
magnifying glass. 
















72 


HYGIENE BY EXPERIMENT 


A. Is a hair smooth or is it scaly? 

B How does the root seem to differ from the rest of 
the hair? 

2. Hair in relation to the scalp. Look closely at the 
hair of some one’s scalp. Does a hair seem to come from 
any depth in the scalp or only from the surface? 

A. How is a hair fastened to the scalp? 

B. What matter do you find on the scalp that looks 
like the scurf that you scraped from the back of youi 
hand? 

3. Effect of rubbing the skin. Using a clean handker¬ 
chief, rub the back of your hand vigorously until the 
skin begins to redden. 

A. Remembering that blopd feeds the hair roots, 
what advantage do you think there may be in thoroughly 
brushing your hair and scalp once or twice a day? 

B. What is the objection to wearing a hat so tight 
that it cuts down the circulation of blood in the scalp? 

4. One cause of headaches and its cure. When you 
have a headache, you can sometimes get relief by rubbing 
the scalp well. Most headaches are due to poisonous mat¬ 
ter in the scalp, and rubbing helps the blood to flow 
along and take away the poison. This poison usually 
comes from overworking the muscles in case of bad eye¬ 
sight, from decaying food in the bowels, from fatigue due 
to loss of sleep and rest, or from foods that should not 
have been eaten. 

A. How often do you have headaches, if at all? 

B. What do you think causes them in your case? 

C. How then can you keep from having headaches? 

Exercise III. Questions on the Foregoing Exercises 

1. Keeping track of the time that it takes for a “black 
and blue” mark, or other mark, at the base of the nail, to 


CARE OF FINGER NAILS, HAIR, AND SCALP 73 


grow out to the end of the nail, about how long do you 
find that it takes a finger nail to grow out? 

2. Why is biting the nails a habit that is bad for the 
mouth? Why bad for the teeth? Why bad for the nails? 

3. What is meant by the phrase “massaging the scalp” ? 

4. Why, in taking care of your hair, should you 
brush it vigorously and for some time? 

5. What do you suppose is the reason for baldness in 
some cases? 

6. Should you take headache medicine when you have 
a headache, or should you remove the cause of the 
headache? 

7. Does a headache ever serve a useful purpose? 

Exercise IV. Questions for Investigation 

1. How do your nails get longer and thicker? 

2. How should your nails be trimmed? 

3. How does your hair grow in length? 

4. How is your hair oiled naturally? 

5. How should your hair be cared for? 

6. Why should you not use a public comb and brush? 

7. What health habits are necessary for the good of 
nails, hair, scalp? 


STUDY ELEVEN 

USES OF CLOTHING 

Beau Brummel was a famous English dandy of a 
hundred years ago. In a play based on his life he is 
made to say something like this: “What a blessing that 
the Lord gave us our bodies bare that we might dress 
them to suit ourselves!” A good many people seem to 
have this same idea — that clothes are mainly for orna¬ 
ment. Nevertheless, the most important reason for 
wearing clothing has to do with the hygiene of the skin. 
The barbarian in lands where the weather is always hot 
wears only a loin cloth, while the Eskimo keeps himself 
clothed in furs. Both of these dress according to the 
climate, and in that respect they practice hygiene. For 
ornament, the Eskimo will have his furs embroidered, 
but he will not cut scallops in his coat or “parka”; and 
the man with the loin cloth will put a brass ring in his 
nose, but he will not wear summer furs. The people 
of some civilized lands are not always so sensible as 
these backward peoples in this matter of dressing as the 
hygiene of the skin requires. To dress in the most 
hygienic manner, we need to know something about 
clothing materials as well as about the body and its 
needs. 

Exercise I. Properties of Different Textiles 

i. Preparing several textiles for study. For a study of 
clothing materials, you will need pieces of cotton, linen, 
and silk, each about the size of a man’s handkerchief; 
also a piece of thin woolen goods weighing no more than 
the piece of cotton cloth. If scales for weighing as little * 
as an ounce or less are not at hand, take a light wooden 

74 • 


USES OF CLOTHING 


75 



Fig. 25. The girls here are examining various textiles. The boy has 
rigged up a balance on which he will get four pieces of cloth to weigh 
the same. 


ruler, stick a pin through the exact center, pin the piece 
of cotton cloth to one end of the ruler, and trim the 
woolen piece to such a size that, when pinned to the 
other end of the ruler, it will balance the cotton piece 
exactly. If silk and linen pieces of cloth are not to be 
had, these experiments can be performed to advantage 
with cotton and woolen cloth alone. There will also be 
needed for the experiments a common drinking glass 
three fourths full of water, a kerosene lamp, a simple 
magnifying glass, and a pan of water. 

2. Testing the heat conductivity of textiles. You need 
first to study the power of the pieces of cloth to conduct 
heat. The sample of silk should perhaps be doubled to 
make it as thick as the samples of cotton, wool, and 
linen. Place a part of the cotton cloth over the end of the 
index finger and then rest the finger against the chimney 
of a burning lamp at a point about a third of the way 







76 


HYGIENE BY EXPERIMENT 


down from the top of the chimney. Note the number of 
seconds that pass until the finger end gets too hot for 
comfort and is pulled away. Try in the same way the 
heat conductivity of the samples of wool, silk, and linen 
in each case, keeping track of the number of seconds till 
you have to pull your finger away from the lamp chimney. 

A. How many seconds did your finger stand the heat 
for the cotton? for the wool? for the linen? and for the 
silk? 

B. Which of the cloths is the best conductor of heat, 
and which is the poorest conductor of heat? 

3. Conductivity of a metal and of air. With one index 
finger, hold a copper penny at the same spot on the 
lamp chimney against which you held the cloth. The 
end of the other index finger should be held near the 
lamp chimney, on the opposite side, leaving a space 
that corresponds to the thickness of the penny. 

A. Is copper as good a conductor of heat as air is? 

B. Is copper as good a conductor as cloth is? 

C. Is air a good conductor, or is it a very poor con¬ 
ductor of heat? 

4. Effect of crinkly fibers on conductivity. With a 
simple magnifying glass, examine the finest possible fiber 
you can get from each of the samples of cloth. 

A. Which of these textile fibers looks coarsest and 
crinkliest when magnified, and which looks finest and 
least crinkly? 

B. Note that crinkly fibers cause a lot of air to be en¬ 
closed in a textile. What effect does this have on the 
conductivity of the textile? 

C. What is the effect on the conductivity of cotton 
when it is woven with meshlike structure, as it sometimes 
is in underclothing? 


USES OF CLOTHING 


77 


5. Water absorption by different textiles. You learned 
in your studies of the skin that you perspire mainly in 
order to get rid of the extra heat in the body. That this 
loss of heat may go on best, the underclothing should be 
of textiles that will most quickly take up and pass on the 
perspiration. You must, therefore, test your textiles to 
find out their relative power to absorb water. To do this, 
suspend the four samples of cloth so that an inch at a 
lower corner of each piece is in a glass of water by itself, 
the top corner being pinned to a suitable support above. 
After the textiles have hung for a little while with ends 
in the water, what do you find to be their relative powers 
of absorption; that is, which textile is the best absorber 
of water (is damp highest up), which is second best, 
which third best, and which fourth best? 

6. Water-holding power of textiles. The relative 
water-holding power of each sample of cloth is worth 
finding out. You can discover this by pressing down each 
piece, when it has dried, into a separate drinking glass 
three fourths full of water, this level having been marked 
with an ink line on the outline of the glass. When 
taking each cloth out, allow it to drip as much water 
back into the glass as it will. Be sure, too, that each 
textile has become thoroughly soaked before removing 
it from the water. Now compare the loss of water from 
each glass to see the relative water-holding power of 
each textile. Which textile is first in water-holding 
capacity? Which is second, which third, and which 
fourth? 

7. Loss of water from textiles. It now remains to find 
out which textile loses its water fastest, for that is impor¬ 
tant also. Take the four pieces of wet cloth and hang 
them up where they will dry. Watch closely to see which 


78 


HYGIENE BY EXPERIMENT 


one dries first. The silk will usually have the advantage 
here because it is thinnest and most spread out. But 
note especially the cotton and the wool. Which textile 
dries first, which dries second, which third, and which 
fourth? 

Exercise II. Good Textiles for Outer Clothing 

1. How to tell animal from vegetable fibers. In an 

earlier study you learned the difference in textiles by 
examining fibers under a magnifying glass. You can 
also tell the kind of fiber of which a piece of cloth is 
made by putting an end of the cloth into a drinking glass 
partly filled with a water solution of potassium hydroxid. 
This chemical will dissolve woolen and silk threads, 
which are animal fibers; but it will not dissolve cotton 
and linen threads, which are vegetable fibers. Let some 
pupil show the rest of the class how this works out. 
How can you tell animal from vegetable fibers in any 
textile ? 

2. Distinguishing cotton from linen. Sometimes it is a 
little troublesome to decide with certainty whether a 
piece of cloth is cotton or linen. But there is a test that 
you can easily apply. Put a drop of glycerin on a piece 
of each kind of goods that you have been experimenting 
with, and let the goods lie for a few minutes. Which 
kind of cloth lets light go through best when glycerin 
is put on it? 

3. Clothing and body warmth. Whether clothing in 
itself gives any warmth to the body, an experiment can 
be made to show. For this experiment you will need 
two big bottles with water equally warm in them and 
two with water equally cold in them. Tou must now 
wrap a woolen cloth around one of each pair of bottles, 


I 


USES OF CLOTHING 


79 


leaving the other bottles unprotected. After a little 
while, use a dairy thermometer to see if there is any 
difference in the temperature of the two cold bottles and 
likewise of the two warm bottles. Which of the warm 
bottles stayed the warmer, and which of the cold bottles 
stayed the colder? What did the woolen cloth do for 
both bottles? 

Exercise III. Questions on the Foregoing Exercises 

1. Why does a cotton sheet feel so much colder on 
your bed in winter than a woolen blanket? 

2. Why does a piece of iron feel colder to your touch 
than a piece of wood, when both are lying out-of-doors 
in winter? 

3. How can cotton underwear be so woven as to 
make it as good a non-conductor as woolen underwear 
is? 

4. Which kind of underwear can take up perspiration 
more quickly, cotton or woolen? 

5. Which kind of underwear can hold the larger 
amount of perspiration, cotton or woolen? 

6. Which kind of underwear can give up its perspira¬ 
tion more quickly, cotton or woolen? 

7. Which is the cheaper, cotton underwear or woolen 
underwear? 

8. As to ease with which underwear can be laundered, 
which is the better for underwear, cotton or wool? 

9. What are five reasons why cotton underwear is 
better for most people than woolen? 

10. What are two ways to tell cotton cloth from 
woolen cloth? 

11. What are three hygienic reasons why we wear 
clothing? 


8o 


HYGIENE BY EXPERIMENT 


Exercise IV. Questions for Investigation 

1. Why do people living and working in warm houses 
in winter time not need to wear very much heavier 
underclothing in the winter than in the summer? 

2. How should such people prepare to go out into the 
cold? 

3. Why should you not keep on your overcoat or 
cloak and your overshoes, when coming out of the cold 
to remain for some time in a warm room? 

4. What should you do if your clothing or shoes get 
wet, especially in cold weather? 

5. Make an outline here of a sole of a shoe that is 
hygienic in shape. 

6. What health habits should you practice with regard 
to clothing and footwear? 


STUDY TWELVE 

THE BRAIN AS THE HOME OF THE MIND 

We occasionally hear it said of a man that he has 
brains or that he lacks them, and we take the remark 
to mean that the man has a good mind or a poor one. 
The idea is correct, too, that the quality of the mind de¬ 
pends on the quality of the brain. To make clear some 
points about the mind that we have so far taken for 
granted or not known at all, we shall devote this Study 
to the brain. 

Secure the fresh brain of a slaughtered animal, as a 
sheep or a hog. Try to get it with as much of the spinal 
cord and as many nerves attached to it as may well be. 
Keep the brain in a ten per cent solution of formaldehyde 
for a few days to sterilize and harden it before using it 
for study. Of course, a brain model can be used, but it 
will not be so satisfactory as a real brain. 



Fig. 26. Models of the brains (left to right) of a fish, a frog, an alligator, 
a dog, and a man. Notice how the proportion of the brain used for 
learning becomes larger and larger as we pass from the lower animal 
groups to the higher. The models shown are not in scale, of course. 

8l 







82 


HYGIENE BY EXPERIMENT 



Fig. 27. Side view of a sheep’s brain. In your 
notebook make a simple drawing of this biain, 
and then label the various parts of the brain as 
they are described in the text. 

Exercise I. Learning about the Brain and Nerves 

1. The cerebrum. Examine the largest part of the 
brain, the forebrain or cerebrum , consisting of two parts 
or hemispheres separated by a deep fissure. This is the 
part of the brain that works most when you have sensa¬ 
tions and when you have ideas. This is also the part of 
the brain that is used when you perform a willed act, 
that is, an act controlled by an idea. It is the seat of 
“common sense,” that is', of good judgment about com¬ 
mon things. It may be used to control the rest of the 
brain and nervous system, and it is what keeps you 
from being a mere animal. Whenever you control your 
anger or your fear, your top brain is working at its 
best. Write a little description of the cerebrum as you 
have seen it. 

2. The cerebellum. The next largest part of the brain 
is called the “little brain,” or cerebellum , which has a 
great deal to do with habits, and with the power to 




THE BRAIN AS THE HOME OF THE MIND 83 



Fig. 28. The half of a sheep’s brain that has been 
cut in two the long way, to show the inner parts. 
Make a drawing of this section and label the parts. 


balance your body. Write a little description of the 
cerebellum. 

3. The medulla oblongata. The cerebellum is fastened 
to another part of the brain called the medulla oblongata. 
This medulla oblongata takes care of the breathing, 
digestion, heart action, and circulation. It also controls 
many of the workings of the body that help you to 
grow and be healthy. Write a little description of the 
medulla. 

4. The spinal cord. Find the stump of the spinal cord 
at the lower end of the medulla. If the spinal cord were 
all there, it would be as long as the backbone of the 
animal. The spinal cord is the part of the nervous sys¬ 
tem that takes care of a great many little acts that you 
do not have to think about, such as jerking your hand 
back after touching a hot stove. Acts like this are 
called reflex acts. Write a little description of as much 
of the spinal cord as you can see. 

5. The nerves. It may be that stumps of nerves will 







8 4 


HYGIENE BY EXPERIMENT 


be found coming out from the medulla oblongata of the 
brain you have been examining. Nerves are white, 
coarse fibers that serve to carry messages between the 
brain and the spinal cord on the one hand, and the 
parts of the body on the other. Write a little description 
of the stump of a nerve, if you find one. 

6. Summary. Label the parts and set down the uses 
of the brain as shown in Figure 27. 

7. The inside of the brain. Now cut the brain in two, 
the long way. Lift up the rear end of the cerebrum and 
note that it covers a big, whitish lump as big as the 
outer joint of your thumb. This is called the thalamus 
and it is a very interesting and highly important part 
of the brain. It is the part of the brain that works most 
when an animal becomes frightened, or angry, or cries; 
that is, it is the seat of instinctive behavior. It is also 
the seat of feelings, and is active when one feels good or 
bad. When a human being gets excited and acts as lower 
animals do, his cerebrum has about quit work and 
only his thalamus and other lower parts of his brain 
are in action. Label and write down the uses of the 
parts of the brain pictured in Figure 28. 

Exercise II. Learning about the Senses 

1. The sensations arising in the skin. Touch your 
hand to a warm object. This gives a sensation of warmth. 
Touch your hand to a cold object. This gives a sensa¬ 
tion of cold. Place your finger against some object that 
is neither hot nor cold. This gives the sensation of touch 
or pressure alone. Gently press a pin point against the 
skin. The sensation of pain arises. These are the four 
sensations coming from the skin. 

A. What do you think a sensation is? 


THE BRAIN AS THE HOME OF THE MIND 85 


B. What are the four sensations from the skin? 

C. How may pain be a kindness of nature? 

2. The sensations from the tongue. Put sugar on your 
tongue, then common salt, then drops of vinegar or 
lemon juice, and finally a very tiny bit of quinine. What 
are the four taste sensations that your tongue may give 
you? 

3. The sensations from the eye. Take a small piece of 
very bright red paper, about as big as a cent, and lay it 
on a larger piece of white paper. Make a dot in the 
center of the piece of red paper, and look at this dot 
very steadily while you count 40. Now look at some 
spot on the white paper. The color that you now see as 
you look at the white paper is the second of the six pri¬ 
mary eye sensations. In a similar way look at a piece of 
blue paper on the white sheet, and then at a piece of 
very black paper. What are the six primary sensations 
of the eye? 

4. The sensations from the ear. Strike single tones on 
a musical instrument, and then strike a lot of tones all 
together. What two different kinds of sensations come 
from the ear? 

5. Other sensations. Write in your notebook the 
names of as many other sensations as you know. 

Exercise III. Questions on Mental Hygiene 

1. What do you think your mind is for? 

2. What is meant when people talk to you about 
improving the mind? 

3. Why must we have sleep? 

4. At what time do you usually go to bed? At what 
time do you usually get up? About how long, then, do 
you sleep every night? 


86 


HYGIENE BY EXPERIMENT 


5. Do you always have a window open while you sleep? 

6. If you have ever started to get angry and then de¬ 
cided to keep calm, what part of your brain did you bring 
into use? 

7. When children become angry easily or pout a great 
deal, how can they be made to get over such bad habits? 

8. Is it possible for one who is scared easily to get over 
this unfortunate tendency? 

9. How can a “cry baby” cease to be such a person? 

10. If a boy or girl has an unhappy disposition, what 
do you think he or she could do to be freed from it? 

11. How could a boy who “thinks he’s smart” make 
himself more agreeable to his playmates? 

12. What are some ways of doing that will help you 
to be cheerful during a greater part of the time? 

Exercise IV. Questions for Investigation 

1. What is the nervous system? 

2. What is the work of the brain? 

3. What is the work of the spinal cord? 

4. What two different kinds of work do nerves do? 

5. Why do you need rest after hard work? 

6. How long should a boy or girl of your age sleep? 

7. What is the use of a sensation of pain? 

8. What useful purpose do headaches serve? 

9. What are some of the things that cause headaches? 

10. What is a habit? 

11. How can you break a bad habit? 

12. How can you form a good habit? 

13. Make a list of good habits of mind and behavior. 


STUDY THIRTEEN 

TAKING CARE OF YOUR EYES AND EARS 

Doubtless you know something of the story of Helen 
Keller, that wonderful woman who is both blind and 
deaf. In one of her books she says: “My hand is to me 
what your hearing and sight together are to you. It is 
the hand that binds me to the world of men and women. 
The hand is my feeler with which I reach through dark¬ 
ness and seize every pleasure my fingers touch.” 

People who nave good eyes and ears do not realize how 
useful and at the same time how delicate these organs 
are until they begin to fail, and for lack of knowledge 
boys and girls sometimes sadly abuse their eyes and ears. 
If your eyes and ears are still good, you will surely be 
glad to know how to keep them so. 

Exercise I. Studies of the Eye 

1. Examining an animal’s eye. If your teacher feels 
that it can be conveniently done, she will get from a 
butcher the eye of an ox or of some other animal for 
your study. By dissection she will give you a chance to 
see what an eye is made of. What are some of the things 
you find on the inside of an eye? 

2. Studying an image. Take a lidless cardboard box 
that is about an inch each way in size, and in the center 
of the bottom make a good, clear hole with a darning 
needle. Cover the open top of the box with tissue paper, 
fastening the paper to the sides with paste. Take the box 
into a dark room and hold it so its tissue-paper side is 
facing you. Two or three inches back of the hole in the 
bottom hold a burning match or candle, and then observe 
the image of the flame (upside down) on the tissue paper. 

87 


88 


HYGIENE BY EXPERIMENT 


Now enlarge the hole in the cardboard until it is about 
one fourth of an inch in diameter. Hold the box and 
the flame as you did before, and see how the image looks 
this time. If you have a lens of a simple microscope, lay 
it over the hole in the box, and by shifting the match or 



Fig. 29. This diagram of the human eye shows how light rays travel 
from an object to the retina and form an image there. The image is 
upside down, of course, but the brain interprets the image correctly. 


candle flame toward the lens and away from it, you 
should succeed in getting a clear image of the flame on 
the tissue paper again. Now hold the flame somewhat 
farther off. The image is then like the image that a near¬ 
sighted person gets. Hold the flame nearer and you get 
an image like the image that a far-sighted person ordi¬ 
narily gets. If in this last case, you put a lens of a pair of 
glasses for a far-sighted person back of the microscope 
lens you are already holding back of the hole in the box, 
you will see why far-sighted people wear glasses. From 
this experiment what have you learned that explains 
why people wear glasses? 

3. Effect of light on the pupil of the eye. While looking 
at your own eye in a mirror, hold a strong light near 
one of your eyes and a little to one side of the line be¬ 
tween your eye and the mirror. Now move the light a 
foot or two away from your eye and then back again 
close to the eye. While doing this, note how the pupil 











TAKING CARE OF YOUR EYES AND EARS 89 


of the eye changes in size, and remember that it is 
harder work for the eye to make the pupil small than to 
make it large. What is the effect of a weak light and what 
is the effect of a strong light on the size of the pupil of 
your eye? 

4. The best source for a light in reading. Try reading 
a book while a strong light is shining directly on the page 
and also into your eyes. Now do some reading while the 
light is at the rear of the head and a little to the left or 
right of it. Recalling what you learned from Experiment 
2, and judging from your own experience, in which case 
is it harder on the eye to read, with the light in front or 
with the light to the rear of the head while reading? 

5. The best source for light in writing. Try writing 
with a pencil while a strong light comes over the left 
shoulder, and again when it comes over the right shoulder. 
It will make a difference, of course, whether you write 
with your right hand or with your left. When you are 
writing, should the light for you come over your left 
shoulder or over your right shoulder, as you find by 
trial? 

6. Getting cinders out of your eye. While the hands 
are very clean, take a small and very clean pencil and 
seat yourself before a mirror. Now roll the upper lid of 
one of your eyes over the pencil so that you can see the 
under surface of the lid. If you had a small particle 
under your eyelid, some one could now easily remove it 
with the corner of a clean handkerchief. Have you suc¬ 
ceeded in getting your lid turned up without hurting the 
eyeball? 

7. Testing your eyesight. The teacher will test your 
eyesight and that of all the other pupils also, using any 
ordinary eye chart and following the directions that go 


I 


90 HYGIENE BY EXPERIMENT 

with it. How does your right eye test? Your left eye? 
Does the test show that you need glasses? 

Exercise II. Studies of the Ear 

1. Examining the ear canal. Adjust yourself so that a 
strong light shines into the canals of one of your ears. 
Place a mirror on the side of the head that the light 
shines on. Hold a hand mirror in front of your eye, so 
that it faces halfway between the other mirror and your 
eyes and so that you can see an image of your ear in the 
hand mirror. You should find that the ear canal leads into 
the head to the depth of about an inch, and is closed by 
a membrane called the drumhead. Behind this drumhead 
are the other important organs of hearing. Do you suc¬ 
ceed in seeing your drumhead, and is your ear canal rea¬ 
sonably free from wax? 

2. Testing your hearing. You should have your 
hearing tested, as well as your eyesight. To test your 
hearing, you need to sit with your back toward your 
teacher and twenty feet away, keeping one ear closed. 
The teacher will now whisper any five letters of the alpha¬ 
bet not in order, which you will write down on paper, one 
at a time. Test the other ear similarly. Several pupils 
can be tested in this way at once. If you cannot hear 
what the teacher whispers, come closer to the teacher 
until you do hear. If you hear at twenty feet, write 
20/20; if at fifteen feet, write 15 /20; and so forth. Fifteen 
twentieths would mean that your hearing is only three 
fourths as good as most people’s hearing. 

A. How does your right ear test? 

B. How does your left ear test? 


TAKING CARE OF YOUR EYES AND EARS 


91 


Exercise III. Questions on the Foregoing Exercises 

1. What has nature provided to protect your eyes? 

2. How do you direct your eyeballs sidewise and up 
and down? 

3. Why is it important for you to wear spectacles if 
your eyes are not as good as they ought to be? 

4. Why should you have light that is carefully ad¬ 
justed, when using your eyes? 

5. How can you rest your eyes? 

6. Do you have earache often? 

7. If foul odor comes from either of your ears, what 
does this show? 

8. Do you have to watch the teacher’s mouth closely 
to understand what she is saying? 

Exercise IV. Questions for Investigation 

1. Why should you not rub your eyes? 

2. How may your eyes become diseased? 

3. Find and record in your notebook at least ten rules 
for preserving your eyesight. 

4. How do you hear sound? 

5. What is ear wax for? 

6. Why should you be very careful about putting any¬ 
thing in your ear canals? 

7. What are some good rules you have found for 
taking care of your hearing? 


STUDY FOURTEEN 


WHAT TO DO IN ACCIDENT AND EMERGENCY 

A village of 1149 people would represent an average¬ 
sized village in the United States. If all the people of 
such a village were to die in one year, that would surely 
be counted a great calamity. Yet the coroner of the city 
of Chicago reported that in one year, not long ago, 
exactly that number of people were killed by falling 
downstairs. Four thousand others were reported crip¬ 
pled in the same way that year in Chicago. Very high- 
heeled shoes were then in fashion, and that may have 
caused more than the usual number of people to trip 
and fall; but always and everywhere a large number of 
people are being injured in one way or another. 

The world is always looking for the boy or girl who 



Fig. 30. A class of fifth-grade boys and girls who have been studying 
how to give aid in cases of accident. They are demonstrating the method 
of carrying an injured person and also methods of bandaging. 


92 















WHAT TO DO IN ACCIDENT AND EMERGENCY 93 


knows how to do things. Nowhere is this more true 
than in the case of daily accidents. You are now to 
study how to help others as well as yourself, in case of 
injury, d o do this you will need to have at hand a copy 
of the American Red Cross Abridged Textbook on First Aid. 

Exercise I. Bandages 

1. Kinds and materials for making. 

A. Make a drawing in your notebook of a triangular 
bandage such as is pictured in the book referred to above. 

B. Make a drawing of a roller bandage. 

C. Make a drawing of a four-tailed bandage. 

D. What are three different kinds of textiles out of 
which bandages are usually made? 

E. What are three different purposes for which ban¬ 
dages are used? 

2. Making bandages. Obtain the material for one 
sample of each of the three shapes of bandages, and 
practice making the following varieties of bandages, so 
that you can give your class and teacher, and perhaps 
others, a demonstration: A. Eye bandage. B. Neck 
bandage. C. Jaw bandage. D. Head bandage. E. Cir¬ 
cular bandage. F. Reverse bandage. G. Figure-eight 
bandage. H. Forehead bandage. I. Back-of-head band¬ 
age. J. Nose bandage. K. Chin bandage. L. Hand 
bandage. M. Arm-sling bandage. 

Exercise II. Treatment of Injuries 

1. Wound dressing. 

A . What materials are needed to make a good dressing 
for an ordinary wound? 

B. How would you dress an ordinary wound on the 
back of someone’s hand? 


94 


HYGIENE BY EXPERIMENT 


2. Treating bloodless injuries. Show how to give 
proper treatment in the following cases, using someone to 
help who will make believe that he has been injured: 

A. Bruises. B. Strains. C. Sprains. D. Dislocation of a 
finger. E. Fracture of the right forearm. 

3. Treating bloody injuries. 

A. How would you treat a wound ( a ) when the 
blood only oozes out, (b) when it flows out steadily, and 
(c) when it pulses out in jets? 

B. How would you treat nosebleed? 

C. How would you treat dog or cat bites? 

Exercise III. Treating Injuries Due to Heat or Cold or 

Suffocation 

1. Burns. 

A. What is a good general rule (a) for preventing fires, 
and (b) for putting out fires? 

B. How can you best extinguish fires in clothing that 
you have on? 

C. How should you treat (a) a simple burn, ( b ) a 
blistered burn, and (c) a deep burn? 

2. Sunstroke and heat exhaustion. 

A. How can you avoid sunstroke? 

B. How should you treat a case (a) of sunstroke, and 
(b) of heat exhaustion? 

3. Freezing. 

A. How should you treat a case of frostbite? 

B. How should you treat a case of frozen feet or 
hands? 

4. Suffocation, electric shock, and poisoning. 

A. Give a demonstration of the Prone-Pressure 
method of artificial respiration in case of suffocation. 

B. Give a demonstration of the Sylvester method. 

C. How should you treat a case (a) of drowning, (b) 
of electric shock, or (c) of poisoning? 


PART TWO 

Community Hygiene 

TO THE BOYS AND GIRLS 

Till some twenty years ago, sanitary drinking foun¬ 
tains and individual drinking cups were almost unknown 
in public places. In nearly every school there was an 
open pail of drinking water, and pupils and teachers all 
drank from the same tin drinking cups. In those days 
contagious diseases used to spread rapidly, and particu¬ 
larly among school children. But at Herington, Kansas, 
something happened in October, 1906, that compelled 
people to think. Diphtheria had broken out in the town 
in a very violent form, and a good many schoolboys and 
schoolgirls were stricken. Five school children were 
among the first to die. The city board of health and the 
board of education held a joint meeting to see what they 
might do. At this meeting Dr. George Klepinger, the 
city health officer, declared that very definite and strict 
sanitary measures must be put into operation. Among 
these measures were the immediate abolishment of the 
public drinking cup and the installation of sanitary 
drinking devices at each of the school buildings. Another 
measure that he recommended was that during the epi¬ 
demic each child should be examined by a competent 
physician before being allowed to enter a schoolroom. 

These measures were put into effect, and within four 
weeks every case of diphtheria had disappeared from the 
town. So well was the board of education pleased 
with the remarkable success of the abolishment of the 
public drinking cup that the order prohibiting it was 
made permanent. Thus Herington, Kansas, was the 

95 


96 


HYGIENE BY EXPERIMENT 


first town in the United States absolutely to abolish the 
use of the common drinking cup in public schools. It is 
an interesting fact that not another case of diphtheria 
occurred in Herington for almost five years. That case 
was immediately quarantined, and no other child caught 
the disease. 

The word “sanitation” comes from the Latin word 
“sanitas,” meaning “health,” just as the word “hygiene” 
comes from the Greek word for “healthful.” We, however, 
use the word “hygiene” with particular reference to that 
field of health which has to do with our own bodies; and 
we apply the word “sanitation” to the field of community 
hygiene. Sanitation is the science which deals with the 
problem of making oar surroundings healthful. 


STUDY FIFTEEN 

BACTERIA, THE SMALLEST OF PLANTS 

Germs are such very small living things that you can¬ 
not see them with the naked eye. But if you can get 
several thousands or millions of them together, they will 
make a little mass about the size of a pinhead, which you 
can see very readily. You will not have to have a micro¬ 
scope to study germs in such a mass, but you can learn 
much more about them with a compound microscope. 
Some germs are plants and some are animals. The plant 
germs are called bacteria and the animal germs are called 
protozoa. 

If you prepare the right sort of place for a single bac¬ 
terium to grow, in a few hours or a few days there will be 
so many of them that the colony can easily be seen with 
the unaided eye. This is because a vigorous, growing 
bacterium divides into two about every half-hour, and 
each of the divisions, or new germs, does the same. 
Your teacher will perhaps make a “germ garden” or 
culture medium , as the doctors call it, in which germs 
will grow, and then you can learn for yourself many 
things about bacteria. 

Exercise I. How to Make a Germ Garden 

Two ways of making a germ garden are here described, 
the first being the more complex, but also the more 
satisfactory when done. The second way is simpler, and 
it does not require any materials not found around an 
ordinary home. 

i. The agar preparation. Prepare a half teacup of 
clear beef broth and add two cups of hot water and one 
teaspoonful of brown sugar. Do not use dried beef or 

97 


98 


HYGIENE BY EXPERIMENT 



Fig. 31. Examining a germ garden. The bottle at the 
left contains agar preparation, and from it each of the 
six germ gardens on the table were supplied with culture 
medium. 


bouillon cubes in preparing your broth; and; if you can 
get it, use grape sugar, or glucose, in preference to the 
brown sugar. To your preparation add two per cent, 
by weight of agar, a powdered, gelatinous product of an 
Oriental seaweed, which is obtainable at the more com¬ 
plete drug stores. Now bring the mixture to a boil, stir¬ 
ring it thoroughly. Filter through a funnel filled with 
wet absorbent cotton. Collect in a bottle all the material 
that will strain through, add a little soda and salt, and 
stopper the bottle loosely with a plug of absorbent cotton. 
Now set the bottle in a covered metal vessel, and pour 






99 


BACTERIA, THE SMALLEST OF PLANTS 

• 

enough water into the vessel to bring the water level up 
to the neck of the bottle. Bring the whole to boiling for 
an hour on each of three successive days. This material 
will solidify on standing and may be kept for some time. 
When about to use the material, put the bottle in hot 
water again to melt the contents, and pour a small 
quantity of it into each of at least twenty thoroughly 
sterilized test tubes, or other receptacles. Stopper the 
mouths of the receptacles with plugs of absorbent cotton 
that have been sterilized by being highly heated in an 
oven for 15 minutes. Allow the contents of the recepta¬ 
cles to solidify by cooling while the tubes or bottles 
stand at an angle of about 45 degrees. What, now, is the 
appearance of your germ garden prepared from agar? 

2. The potato preparation. The other way to make 
a germ garden consists in taking a few healthy raw 
potatoes and cutting from them as many pieces, an inch 
long and three eighths of an inch square, as there are to 
be experiments. Take an equal number of test tubes 
or small bottles, each of which will admit an unbroken 
piece of potato. Now place all the receptacles in a cov¬ 
ered vessel nearly full of hot water, and boil for 3 minutes. 
Meantime, have at hand some clean, dry, and previously 
baked absorbent cotton, and, if possible, carry out all 
directions here without stirring up any dust whatever. 
Sterilize, by boiling for 15 minutes, a pair of pliers or a 
wire bent double to serve as a substitute. Lift a test 
tube or vial from the water with the pliers, put into the 
tube a piece of potato, add a drop or two of red ink, and 
insert a loose plug of cotton into the mouth of the tube 
as a stopper. Now set the tube aside, being careful not to 
let the water in it touch the cotton. In the same manner 
drop each remaining piece of potato into a test tube. 


100 HYGIENE BY EXPERIMENT 

Now boil the water in each test tube for one minute, not 
letting the water boil up against the cotton. This 
boiling can be done by holding the lower ends of the 
tubes in a flame, or by lowering the tubes into a teakettle 
of boiling water. 

Set the tubes aside for 12 hours, and then boil each 
again for a minute. At the end of another 12 hours, boil 
the tubes once more for a minute. After this last boiling 
remove the cotton stopper, holding it so that the end 
that belongs in the test tube will not touch anything. 
Pour off all the water you can, being careful not to spill 
the potato, reinsert the cotton stopper, and your culture 
medium is ready for use. If this has all been done care¬ 
fully, there should now be no bacteria or mold or yeast 
in the test tubes. The tubes may be kept for use any 
number of days later, so long as the potato in them con¬ 
tinues to be moist. If test tubes and cotton are not 
available, use jelly glasses with their lids, and a larger 
slice of potato. The red ink is used to color the potato 
and make it easier to see the little white patches of bac¬ 
teria that should appear in some of the experiments that 
you are to undertake. 

3. Making the experiments. The germ-garden vessels 
should be distributed among the members of the class, 
giving each pupil one or more experiments to look after. 
It will take three or four days, under favorable condi¬ 
tions, to develop bacterial colonies sufficiently numerous 
in germs to show up little white patches on the back¬ 
ground of the germ garden. Our purpose is now to find 
out some places from which germs come and some 
conditions, both favorable and unfavorable, for their 
growth. 


BACTERIA, THE SMALLEST OF PLANTS 


IOI 


Exercise II. Where Germs Are Found 

1. Germs from the tongue. Take a long, thin strip of 
sheet metal, which must be sterilized by heat each time 
before it is used, and scrape the tongue with it. (A knife 
would do very well, but the heat might ruin the tem¬ 
per of the blade.) Carefully remove the germ-garden 
stopper or lid, transfer some of the scrapings to the 
surface of the “garden” and promptly replace the cover. 
Set the vessel aside in a dark place where the temperature 
ranges from 70° to 90° Fahrenheit. A thermos bottle 
containing water of the right temperature is an ideal 
place in which to set your germ-garden vessel. The water 
in the thermos bottle should not cover the tube. The 
water in the bottle should be renewed often enough to 
keep the temperature up. In three or four days report 
whether small white patches have appeared on the sur¬ 
face of your “garden.” What is the result, and what have 
you learned? 

2. Germs from the teeth. Do as directed in Experi¬ 
ment 2, only this time use scrapings from the teeth. 
What is the result and what have you learned? 

3. Germs from the breath. Do as directed in Experi¬ 
ment 2, but instead of using the tongue scrapings, 
breathe into the “garden.” What is the result, and what 
have you learned? 

4. Germs from a pencil point. Do as directed in 
Experiment 2, but instead of using the tongue scrapings, 
touch the garden with the point of an old pencil. What 
is the result and what have you learned? 

5. Germs from pond water. Take one of the unused 
germ gardens and put into it a drop of ordinary pond 
water. Keep for three or four days in any place that is 


102 


HYGIENE BY EXPERIMENT 


ordinarily warm and dark. What is the result, and what 
have you learned? 

6. Germs from fresh milk. Do as in Experiment 5, 
but use a drop of fresh milk instead of water. What is the 
result and what have you learned? 

7. Germs from decayed fruit. On the germ garden 
in another tube, place a bit of decayed fruit or vegetable 
matter, and keep the tube in a place that is moderately 
warm and dark for three or four days. What is the result 
and what have you learned? 

8. Germs from dust. Set an unused garden with its 
cover off in a dusty room for 10 minutes, and then keep 
in a moderately warm, dark place for three or four days. 
What is the result and what have you learned? 

9. Germs from a finger nail. Put on an unused germ 
garden some scrapings from under a finger nail, and then 
keep the tube in a moderately warm, dark place for 
three or four days. What is the result and what have 
you learned? 

10. Germs from a drinking cup. Do as directed in 
Experiment 10, only this time use scrapings from a com¬ 
mon drinking cup, if you can find one anywhere in use. 
What is the result and what have you learned? 

11. Germs from the skin. Do as directed in Experi¬ 
ment 10, only use scrapings from the hand. What is the 
result and what have you learned? 

12. Germs from pus. Do as directed in Experiment 
10, but this time use some pus from a pimple or a sore. 
What is the result and what have you learned? 

13. Germs from a house fly. Permit a fly to walk 
over a garden, allow it to escape, and then replace the 
stopper. What is the result after several days, and what 
have you learned? 


BACTERIA, THE SMALLEST OF PLANTS 


Exercise III. Favorable and Unfavorable 
Conditions for Germs 

1. Effect of dryness. Heat one of the unused germ 
garden vessels until the garden is quite dry, and then 
put into it a bit of decayed fruit or vegetable matter. 
Keep in a moderately warm and dark place for several 
days. What is the result and what have you learned? 

2. Effect of sunlight. Put some tongue scrapings on a 
germ garden and keep the garden three or four days in 
direct sunlight as much as possible. What is the result 
and what have you learned? 

3. Effect of low temperature. Do as directed in 
Experiment 2, but keep the garden in a cold place, as a 
refrigerator, for three or four days. What is the result 
and what have you learned? 

4. Effect of a germicide. Do as directed in Experiment 
2, but add a drop or two of formalin or a 5 per cent, solu¬ 
tion of carbolic acid to the garden, just after putting 
the tongue scrapings on it, and keep in a warm, dark 
place. What is the result and what have you learned? 

5. Effect of strong acid. Do as directed in Experiment 
2, only this time use any strong acid, other than carbolic 
acid. What is the result and what have you learned? 

Exercise IV. Questions on the Foregoing Exercises 

1. What are fifteen different places in which bacteria 
can ordinarily be found? 

2. What are five conditions unfavorable to the growth 

of bacteria? 

3. What are five conditions favorable to the growth 
of bacteria? 

4. Why is each of the following practices bad: (a) 
spitting in public places; ( b ) putting pencils into the 
mouth; (c) moistening the thumb in turning the leaves 


104 


HYGIENE BY EXPERIMENT 


of a book; ( d ) licking court-plaster before putting it on a 
sore; ( e ) kissing little babies; (/) scratching a sore with 
the finger nails; (g) drinking from a glass some one else 
has used? 

5. What are three other unhygienic practices? 

6. Why should one let sunshine into a sleeping room? 

7. Why is it not well to use a feather duster in cleaning 
a room? 

8 . Why is it undesirable to permit a fly to walk on 
prepared foods? 

Exercise V. Questions for Investigation 

1. What is the difference in the meaning of the words 
bacterium and bacteria? 

2. Do bacteria belong to the plant kingdom or to the 
animal kingdom ? 

3. How big is a bacterium? 

4. What are the three different shapes of bacteria? 

5. What makes anything decay? 

6. Why does the skin carry so many germs? 

7. What are some kinds of bacteria that are useful to 
man ? 

8. Which kind of bacteria is most numerous: the use¬ 
ful, the useless, or the injurious? 

9. How do bacteria live through the winter or through 
a very dry time? 

10. Make a list of,health habits that will help to reduce 
the danger of catching germ diseases. 


STUDY SIXTEEN 

PROTOZOA, THE SMALLEST OF ANIMALS 

We have just been studying the interesting little 
plant germs known as “bacteria,” but there are also 
many germs that are tiny animals. These germs that 
are tiny animals are called protozoa. If we are talking 
about only one of them, we call it a protozoan. Protozoan 
germs are usually a little larger than bacterial germs. 
Several of the protozoa are just large enough to be seen 
with the naked eye, if one’s vision is excellent. One of 
these kinds you are now about to study. These tiny ani¬ 
mals are longer than most other protozoans, and they 
get their name, paramecia , from a Greek word meaning 
“oblong.” A single one of them is called a paramecium. 
Paramecia are entirely harmless and are found nearly 
everywhere in fresh-water ponds and along the shores 
of streams and lakes. 

Exercise I. Getting Protozoa Ready to Study 

i. Developing a crop of paramecia. As material for 
these experiments, there will be needed what is called a 
hay infusion , and this should be started by some pupil 
ten days or two weeks before the class takes up the study 
of protozoa. To make the infusion, let the pupil take a 
good double handful of finely chopped timothy hay or 
dead grass and put it into a quart Mason jar. Pour warm 
water into the jar until it is three fourths full. Then 
put the lid on loosely and set the jar aside in a warm 
place for ten days or two weeks, or until a white scum 
begins to form on the water. At first there will be myriads 
of bacteria; and later, when the white scum comes, 
numerous little protozoa of the kind called paramecia will 


105 


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HYGIENE BY EXPERIMENT 



Fig. 32. Using two forms of the simple microscope to study protozoa 
mounted on glass slides. A compound microscope would give a much 
greater magnification. 

develop and feed on the bacteria. If it is possible to 
get a clam and let it decay in the Mason jar of water, a 
good supply of paramecia that are larger will develop. 

2. Finding the smallest animals the eye can see. When 
ready to take up the study of your paramecia, lay a piece 
of black cloth or paper on the table, and on this cloth 
or paper lay a small pane of glass. Now take drops of 
water carrying some of the scum of the hay infusion, and 
transfer them to different spots on the plane of glass. 
Spread out the drops as thinly as possible on the glass, 
and look for extremely minute and numerous, barely 
visible, white specks swimming in the water. These 
are the paramecia. If they cannot be discovered with 
the naked eye, make use of a simple microscope or 
magnifying glass. Describe the paramecia that you have 
seen with the naked eye. 












PROTOZOA, THE SMALLEST OF ANIMALS 107 

Exercise II. Experiments with Paramecia 

1. Behavior of paramecia. Study the tiny specks of 
life until you are able to answer these questions: 

A. Do the little animals tend to collect in small 
groups? 

B. Since these creatures give off a weak acid, explain 
(after completing Experiment 2) why they gather in 
these groups. 

2. Effect of weak acid. Put a drop of ordinary vine¬ 
gar or other acid on a saucer or butter plate and add 
to it ten drops of water from your infusion. Put the 
tiniest possible drop of the weakened vinegar into a 
spread-out drop of water from the top of your infusion, 
using a needle point to transfer the vinegar. Be careful 
not to stir the drop of weakened vinegar around any; 
and let it settle in one single part. What reason have 
you for supposing that paramecia like weak acid? 

3. Effect of salt. To another spread-out drop of infu¬ 
sion with plenty of paramecia in it, add the very tiniest 
grain of salt you can possibly get. Let the salt particle 
remain in the one spot until it dissolves, and then 
watch the paramecia around the spot. How do paramecia 
act toward salt? 

4. Effect of alcohol. As another experiment, transfer a 
very tiny drop of denatured alcohol to another drop of 
water containing many paramecia. What happens to 
paramecia w T hen alcohol is put on them? 

5. The course of a swimming paramecium. Clean off 
your glass thoroughly and spread out on it a good big 
drop of your infusion water. Use a simple magnifying 
glass, if you have it; but with or without it, study the 
way paramecia travel around. Do paramecia travel in 
straight lines, or in broken, or in curved ones? 


io8 


HYGIENE BY EXPERIMENT 


6. How paramecia swim. If you have opportunity to 
examine a mounting of paramecia under a compound 
microscope, magnifying from 80 to ioo times, you may 
observe the paramecium’s peculiar way of swimming. 

A. Does a swimming paramecium keep turning over 
and over as it swims, and if so, why? 

B. Why are some rifle barrels and cannon bored 
with spiral grooves? 

7. Seeing other protozoa. With your compound 
microscope it may be that you can see other kinds of 
protozoa, such as are present in the water of a horse 
trough or in a stagnant pool. If you can find a little 
protozoan called an amoeba , you will be fortunate. What 
other kinds of one-celled animals have you seen? 

8. A protozoan in the human mouth. There is a disease 
of the mouth known as pyorrhea. If possible, examine a 
microscope mounting of matter from the gum around the 
root of a tooth diseased in this way. The microscope 
should magnify 300 or 400 diameters. By close observa¬ 
tion some of the semi-transparent germs of pyorrhea 
may be seen to change shape as an amoeba does. What 
is the appearance of a pyorrhea germ? 

Exercise III. General Questions 

1. How do you think the bacteria and the paramecia 
ever got into the liquid in which you found them? 

2. Since all animals must have air, why do you think 
the paramecia are more numerous near the top of a hay 
infusion? 

3. Why do you think alcohol affects paramecia as it 
does? 

4. What should you expect to be the effect of alcohol 
upon the little amcebalike corpuscles in human blood? 


PROTOZOA , THE SMALLEST OF ANIMALS 109 

5. What are some of the sources in nature where 
protozoa can be found? 

6. Why do we need to know about protozoan germs? 

7. What are phosphorescent protozoa? 

8. Which kinds of protozoa are more numerous, the 
harmful or the harmless? 

9. What is the most important difference between 
protozoa and bacteria, as far as you can find out? 

10. What are some health habits that would lessen the 
danger from protozoan disease germs? 


STUDY SEVENTEEN 

HOW YOUR BODY FIGHTS ITS GERM ENEMIES 

The human mechanism has a wonderful way of keeping 
itself in good working order. Ordinarily a diseased part 
of the body, if given a fair chance , will put itself in good 
condition again. It is the little cells of which the body 
is made that do the work of healing and rebuilding. 
People often talk as if medicines cure the body; but the 
truth is that medicines only help to give the body cells a 
chance to cure themselves. The body, too, is able to 
fight disease germs effectively. But when the germs get 
too numerous, the body must have help if it is to fight 
them successfully. 

Exercise I. The Body’s Outer Defenses Against Germs 

1. One purpose of skin on an apple. Take an apple 
with unbroken skin and in one spot cut through the 
skin. Put a drop of ink on the cut and a drop on the 
unbroken skin. Let the apple stand for a minute or 
two. Now thinly pare the skin from each of the inked 
spots and note the condition of the apple beneath. What 
.seems to be one of the uses of the skin of an apple? 

2. Apple skin and germs. Make an examination of 
several apples, some of which have decayed spots on 
them and some of which show no decay. Note whether 
one group has broken skin and the other not. Can 
apple skins keep germs out as well as they can keep 
ink out? 

3. Infecting an apple. Get a decayed apple and two 
sound ones. Rub the decayed part of the one apple 
against a spot on the sound apple where you have cut 
through the skin with a clean knife. Cut the skin of the 


no 


HOW YOUR BOD Y FIGHTS ITS GERM ENEMIES 111 


other sound apple with a clean knife, but do not touch 
the decayed apple to it. Set the two sound apples in a 
warm place for a week. 

A. What have you learned from this experiment? 

B. Why should rotting apples be at once taken away 
from sound ones? 

4. Examining human skin. Take a clean needle and 
examine the skin of the back of your hand to see if you 
can discover a rather thin layer of skin covering the 
surface of the body. Possibly you may be able to run 
the needle under this outer layer of skin without pain. 
How might this skin serve a purpose such as apple skin 
seems to serve? 

5. The lining of the mouth. Make a similar examina¬ 
tion of the inner lining of the mouth, using a mirror and 
a very clean needle. How can the lining of the cheek 
serve a purpose such as the outer skin serves? 

6. How the nostrils serve as a defense against germs. 
Face away from a strong light and use a hand mirror 
in such a way that you can examine the inside of your 
nose (Fig. 11). The mirror should throw light into the 
nostrils, as well as reflect their image. You should see 
that deep in the nostril the inner surface is quite red 
and carries a slightly sticky moisture. Since the sticky 
moisture in the nostrils is a good germ destroyer, why 
should you breathe through the nose? 

Exercise II. The Body’s Inner Defenses Against Germs 

1. Strong acid as an antiseptic. Take two apples, 
each of which has a rotten spot about as big as a quarter. 
After opening up one of these spots with a knife, pour 
into it several drops of hydrochloric acid (muriatic 


I 12 


HYGIENE BY EXPERIMENT 


acid) and mix this acid about with the apple decay. 
Now set the two apples aside for some days. 

A. What seems to be the effect of strong acid on 
germs of decay? 

B. What could be one of the uses of hydrochloric 
acid that is produced in a healthy human stomach? 

C. What is an antiseptic? 

2. How germs may harm the body. Once germs get 
inside the body there are two ways in which the body 
may suffer harm. Some germs destroy body cells directly, 
and others make a poison that goes over the body 
and does harm in many places. In order to defend itself 
against germs, your body must be prepared both to 
kill germs and to neutralize the poisons that some of 
them make. In the next few experiments a study will 
be made of the way your body does these two different 
kinds of work. To make sure you understand what you 
have just read, you may write the answer to this question: 
What are the two different ways in which germs may do 
harm to the body? 

3. A test for acids. Put a spoonful of water in a 
shallow dish. Dip a piece of blue litmus paper into the 
water and note that it remains blue. Now put a few 
drops of vinegar, lemon juice, or hydrochloric acid into 
the water and dip the litmus paper into it again. To 
what color does an acid change blue litmus paper? 

4. The test for alkalies. Put a spoonful of water in 
another saucer and add to it a few drops of ammonia. 
Test this liquid with pink litmus paper. How can you 
tell when a liquid is alkaline? 

5. Neutralizing an acid. Put a drop of ammonia water 
into the liquid in the shallow dish of Experiment 3, and 
dip a fresh piece of blue litmus paper into it. Does the 


HOW YOUR BODY FIGHTS ITS GERM ENEMIES 113 


paper change color this time? If so, put a few drops 
more of ammonia water into the mixture and then dip 
blue litmus paper into it once more. Repeat, if necessary, 
until neither red nor blue litmus paper changes color in 
the mixture. The acid has then been neutralized by the 
ammonia; that is, its effectiveness has been destroyed. 

6. The process applied. Put a drop of acid in two 
different places on a piece of cloth. Now put a drop of 
ammonia on one of the acid spots and another drop 
on a third spot in the cloth. Let the cloth lie for a day. 

A. What happens to the cloth when it is acted on by 
acid alone? By acid and ammonia together? By am¬ 
monia alone? 

B. Why did not the acid make a hole in the cloth 
when the ammonia was put with it? 

7. How a white corpuscle destroys germs. Take some 
rather fine, dry bread crumbs, color them with red ink, 
and let them dry again. Besides the crumbs, there will 
be needed for this experiment a small quantity each of 
scales of shellac, oil of cloves, and denatured alcohol. 
Put a part of the scales of shellac in a little bottle and 
then fill the vial with denatured alcohol. After the 
shellac has dissolved in the alcohol, pour some of the 
solution on half of the colored crumbs. Allow the shel¬ 
lacked crumbs to dry, taking care to stir them occasion¬ 
ally so that they do not stick together. You are now ready 
for an experiment that will illustrate how the white 
corpuscles of the blood dispose of some of the germs 
that get into the body. 

A. Into a white saucer, pour a teaspoonful of de¬ 
natured alcohol and 3 teaspoonfuls of water. There 
should be one dish to every three or four pupils, each 
group performing the experiment for itself (Fig. 33). 


HYGIENE BY EXPERIMENT 


114 



Fig. 33. A drop of oil of cloves, floating on the water and alcohol in the 
saucer, is enveloping a scale of shellac. The oil of cloves represents a 
white corpuscle, and the shellac represents a germ. The materials on 
the table are a bottle of denatured alcohol, a paper can containing 
shellac, a bottle of oil of cloves, and a beaker of water. 


Float a drop of the oil of cloves on the mixture of water 
and alcohol, and then put a small crumb of the unshel¬ 
lacked red bread close to the drop of the oil of cloves. 
Does the drop of oil take unshellacked bread into itself? 

B. Now put a small crumb of the shellacked bread 
near the drop of oil of cloves. What does the oil of 
cloves do when a piece of shellacked bread comes in 
contact with it? 

C. Put another drop of oil of cloves on the liquid and 
try to "‘feed” it with a small scale of dry shellac. What 
does a drop of oil of cloves seem to do when a small scale 
of shellac is near it? You have seen that a drop of the 









HOW YOUR BODY FIGHTS ITS GERM ENEMIES 115 

oil of cloves will take in a crumb of bread if the bread 
has shellac on it, otherwise it will not. Remember this. 

8. Applying the illustration. Imagine that the bread 
is a germ and that the drop of oil of cloves is a white 
blood corpuscle. Whether a corpuscle takes up a germ 
depends on whether the blood has in it a substance 
that acts like the shellac, covering the germ so that it 
may be taken up. Such a substance which is present in 
healthy blood, is called opsonin , and there is a different 
variety of it for the germs of each disease. The germ¬ 
eating corpuscles in your blood are like spoiled boys, 
who refuse to eat bread unless this or that kind of jelly 
is put on it. 

Write down the definition your teacher gives you for 
the word opsonin. She may get her definition by sim¬ 
plifying the one she finds in a big dictionary. 

9. The source of opsonin in the blood. Just as a boy’s 
mother may refuse to provide jelly except to be eaten 
on bread, so the body refuses to provide in any large 
quantity the opsonin that is needed for any particular 
germ until that kind of germ enters the body. Also, as a 
mother may refuse to set more jelly on the table before 
one dishful has been used, so the human body does not 
renew the supply of opsonin before the present supply 
has been used up. 

Suppose that you have only a little opsonin for pus¬ 
forming bacteria in your blood, and that such bacteria 
get through your skin. The corpuscles will not eat them, 
because there is not enough of the right opsonin to make 
the germs “taste good” to the corpuscles. The bacteria 
then begin to multiply and you have a boil. Meantime, 
what little of the needed opsonin there may be in your 
body is being used up by the germs (soaked up in them) 


HYGIENE BY EXPERIMENT 


116 

though there is not enough to tempt the corpuscles to 
begin their eating. Now it so happens that somewhere in 
the body, though no one knows exactly where, some 
glands go to work to make the opsonin that is required. 
When there is a good supply of the opsonin, the corpus¬ 
cles devour the boil germs, which have grown numerous, 
and your boil or boils get well. After this you will not 
be likely to get more boils until the supply of opsonin in 
your blood runs low again. 

A. What gain is there in having boils, if there is any 
gain? 

B. Write the names of two people to whom you have 
successfully told the story of opsonins in your blood. 

Exercise III. Questions on the Foregoing Exercises 

1. Why is it important for you to keep your skin 
from being scratched or torn? 

2. When germs get into your mouth along with food, 
what keeps them from getting at once into your flesh? 

3. How do your nostrils help to protect you from 
germs? 

4. What happens to many germs in food, when they 
get to your stomach? 

5. Judging by your experiments with acid and 
ammonia, how may the body neutralize poisons in the 
blood? 

6. What have you learned from your experiments 
with oil of cloves, crumbs, and shellac? 

7. Make a list of six ways in which the body defends 
itself against germs. 

8. Why do some people catch germ diseases more 
readily than other people catch them? 

9. What can happen in your blood so that after you 


HOW YOUR BODY FIGHTS ITS GERM ENEMIES 117 


have had a catching disease once you may not have it 
again, at least for a while? 

10. What may happen in your blood so that after 
you have been free from a catching disease for a while 
you may take it again? 

Exercise IV. Questions for Investigation 

1. What are germs? 

2. What other things do germs do beside produce 
disease? 

3. Are there more disease-producing germs than other 
kinds of germs? 

4. Where do disease germs come from? 

5. How do most germs get into the body to produce 
disease? 

6. What are two important rules for preventing germ 
diseases? 

7. In what two ways do germs cause sickness? 

8. What is a toxin? 

9. What is an antitoxin? 

10. How are the commercial antitoxins secured? 

11. What is immunity? 

12. What is vaccination? 

13. How does vaccination for smallpox keep one from 
having smallpox? 

14. How does vaccination for typhoid fever keep one 
from having the fever? 

15. What are some habits you can form to keep 
your body in a higher state of resistance to germs? 


STUDY EIGHTEEN 

HOW YOU CAN HELP T£> COMBAT GERMS 

In stories of warfare carried on by men against their 
fellow men, the names of generals and rulers are given 
much space. But in stories of the warfare of mankind 
against disease, it is the names of great scientists that 
count. Among the chief heroes of this newer and nobler 
warfare are Dr. Edward Jenner, who discovered the 
principle of vaccination, and Louis Pasteur, who invented 
the treatment for hydrophobia. Among lesser heroes 
are the persons who have risked their lives for necessary 
experimentation. What others learned at the cost of 
yeais of study or at the cost of life itself, we may demon¬ 
strate by simple experiments, while we enjoy the benefits 
of their discoveries. We should always keep in mind, 
too, that we are the common soldiers in the army that is 
fighting to win a complete victory for health over the 
tyrant Disease. 

Exercise I. Experimental Studies 

i. Deodorization. 

A. Divide a small quantity of some ill-smelling, 
decaying material into three parts, placing each part in 
a dessert dish or in a tin lid. Cover the first part with 
small pieces of charcoal. Cover the second part with 
pulverized quicklime. Cover the third part with a 
small amount of chlorid of lime. 

After the dishes have stood for an hour or so, use your 
sense of smell to test for odors. Which deodorizer leaves 
the least disagreeable odor — charcoal, quicklime, or 
chlorid'of lime? 

B. Let the charcoal remain for a day or so on the 

118 


HOW YOU CAN HELP TO COMBAT GERMS 119 


decaying stuff used in Experiment A, keeping the 
material in a warm place. Do you find that the charcoal 
stops decay; that is, destroys the germs? 

2. Fumigation with sulfur dioxid. 

A. Secure an ounce of flowers of sulfur. Have at 
hand for a class experiment a pie pan half full of water. 
On it float a dessert dish or the lid of a Mason jar. 
Saturate with kerosene or denatured alcohol a piece of 
absorbent cotton or cotton batting as big as your thumb 
and lay it in the center of the dish or can lid. On this 
cotton pour a teaspoonful of flowers of sulfur and set 
fire to it. The members of the class should in turn smell 
the fumes of the burning sulfur, called sulfur dioxid. 
How does sulfur dioxid smell? 

B. Put some flies or other harmful insects into a 
small wire net and hold the net over the fumes of the 
burning sulfur. What happens to the insects when held 
over burning sulfur dioxid? 

C. Hold several samples of moistened calico or other 
printed cloth over the fumes of burning sulfur; or hold 
fresh blossoms over the fumes. How do sulfur fumes 
affect the colors? 

D. Scrape most of the decay out of a decayed spot in 
an apple. Then hold the apple so that the sulfur fumes 
will penetrate the remaining part of the decay. Set 
the apple aside and note whether the decay continues. 
What is the effect of sulfur fumes on decay in an apple? 

3. Fumigation with formalin. 

A . When formaldehyde is mixed with water it is called 
formalin. As formalin comes from the drug store, it 
usually contains 40 per cent of formaldehyde and 60 
per cent, of water. Take careful note of the appearance 
and odor of a'sample of formalin. If the fumes get into 


120 


HYGIENE BY EXPERIMENT 


your eyes they will make them water, but no real harm 
will come of this. Put some flies or other insects in a 
small net and hold the net over the fumes of formalin. 
What happens when insects are held in the fumes of 
formalin? 

B. Hold several samples of moistened calico or else 
some flowers over the fumes of formalin. Does any 
change occur in the color of the cloth or flowers when 
held in formalin fumes? In what respect is formalin a 
better disinfectant to use than sulfur dioxid? 

4. Disinfection. You will need for this experiment six 
apples or other pieces of fruit, each having a small spot 
of decay on the surface. Scrape out most of the decay. 
Then in each of the decayed spots put a different dis¬ 
infectant, properly labeling each piece of fruit. Keep the 
fruits in a warm place, and after a day or two note the 
effect of each disinfectant on the decay. The dis¬ 
infectants to be used are: hydrogen peroxid; quicklime; 
chlorid of lime; a 5 per cent, solution of carbolic acid; 
denatured alcohol; a 10 per cent, solution of formalin. 

5. Sterilization. Recall the usual process of canning 
fruits and other foods. 

A. What kills the germs when fruit is canned? 

B. Why does canned fruit sometimes spoil? 

C. In your experiments with the germ gardens in 
Study Fifteen, why did you have to heat all the vessels 
so hot and so long? 

6. Pasteurization. You will recall that in your work 
with the germ gardens, you put a drop of fresh milk on 
one of your gardens, and that you thus discovered that 
there are bacteria in fresh milk. Milk does not keep 
well unless something is done to destroy or reduce the 
number of bacteria in it. A common method of keeping 


— 


HOW YOU CAN HELP TO COMBAT GERMS 121 



Fig. 34. A study of disinfectants. Note on the table the apples in 

various stages of decay. 


down the number of germs in it is Pasteurization. 
To learn how milk is Pasteurized, you will need two 
half-pint, or even smaller, bottles of fresh milk. Place 
one of these for 15 minutes in water that has a tempera¬ 
ture of 150° Fahrenheit at the beginning. Then set 
both bottles in a cold place for 24 hours. Examine the 
milk in the bottles at the end of that time. Which keeps 
better, Pasteurized milk or raw milk? Why? 

Exercise II. General Questions 

1. What is deodorization? a deodorant? 

2. What is fumigation? a fumigant? 

3. What is disinfection? a disinfectant? 

4. What is sterilization? 

5. What is Pasteurization, and after whom was the 
process named? 







122 


HYGIENE BY EXPERIMENT 


6. Why should you be careful about the kind of milk 
you drink? 

7. What are some disease germs that are transmitted 
through milk? 

8. Why should all milk vessels be thoroughly scalded 
before milk is poured into them? 

9. What precautions should be taken in milking? 

10. Why is it important that a milch cow be healthy? 

11. Who was Lord Lister? 

12. What health habits should you have in order that 
the body may not have to fight so many germs? 


STUDY NINETEEN 

DISEASES CAUSED BY BACTERIA 

In order to make clearer the story of disease bacteria 
and the way in which they do their deadly work, several 
teachers and a number of pupils at Columbus, Nebraska, 
prepared and gave a little play on the subject. The play 
was a success, and it helped to make the textbook study 
of the subject much more interesting. No doubt your 
teacher and your class could do as well in giving the 
same play or one that you yourselves might devise. 
The play given at Columbus is set out in Exercise I. 

Exercise I. Dramatizing the Story of Contagion 
A Battle for Health 

Place. An untidy living room. 

Characters. Mother, Helen, Elizabeth, Dr. Quack, Darkness, 
Dirt, First Disease Germ, Second Disease Germ, Third Disease 
Germ, Dr. Payne, Father, Ned, Sunshine, Fresh Air. 

Let each pupil taking part make up to show his character , or else 
carry a symbol to show it. 

Helen lies sick on a cot. Germs hide in corners. 

4 

Helen {coughs). Mother, my throat is sore. 

Mother. Then you had better take your medicine. 

Helen. But why must I take that old stuff? It doesn’t do me 
any good. 

First Germ. The more patent medicine, the more fun we’ll 
have! 

Second Germ. This will be our home for some time. 

All Germs. Ha, ha, ha, ha! Now we’re full of glee. We are 
as happy as happy can be. 

Mother. I believe Dr. Quack is coming. 

Third Germ. Here comes our faithful friend, Dr. Quack. 

Enter Dr. Quack 

Dr. Quack. Good afternoon. How ' hy patient getting along? 

Mother. Not very well. She has , Lxt had another coughing 
spell. She will need some more medicine. 

123 


124 


HYGIENE BY EXPERIMENT 


Dr. Quack. Fine! Hadn’t I better leave two bottles this time? 
Two for Si.49. You can double the dose. 

First Germ. Darkness, dirt, disease. We find them in most 
alleys. But our home will be right here, as long as Dr. Quack is 
around. 

Mother (looks at bottle). Why, this is the same kind of medicine 
you gave me when Helen had the measles. What do you think 
is the matter with her now? 

Dr. Quack. Why, er — well, give her plenty of medicine and 
she will be all right in a few days. Good day, good day. I’ll call 
again soon. {Exit.) 

Helen. Mother, he said that the last time he was here, and I 
am no better. Why can’t I have Cousin Jack’s doctor? 

Mother- (thoughtfully) . I will call Dr. Payne. We have wasted 
enough time on Dr. Quack. (Goes out to telephone. Germs get 
frightened.) 

Darkness. I am beginning to feel that my moments are num¬ 
bered here. 

Dirt. Well, you’ll have to go when Dr. Payne comes. We 
must work harder than ever till he comes, for he will send us 
away in a hurry. 

Third Germ. We can hide and fool him for a while. 

Enter Dr. Payne 

Dr. Payne. Good afternoon. What have we here? (Looks at 
patient, examines pulse, and takes temperature. Looks about room.) 
The first thing I must do is to call in my helpers, Sunshine and 
Fresh Air. (Goes to door and calls.) 

Darkness. Farewell, comrades, good luck to you. (Exit.) 

Sunshine. Hurry, for we have much work to do. (Transforms 
room. Sweeps out dirt.) 

Mother. Doctor, what is the matter with Helen? 

Dr. Payne. Your daughter has scarlet fever, so you will have 
to be quarantined. 

Mother. Oh, surely not! Dr. Smith did not quarantine the 
Joneses when their children had what Helen has. 

Elizabeth. Can daddy and Brother Ned come home? 

Mother. Hush, Elizabeth, go and play with your doll. 

Dr. Payne. I will phone the city physician and report the case, 


DISEASES CAUSED BY BACTERIA 


125 



Fig. 35. The visit of Dr. Payne, as one class presented it. The doctor 
has opened the door to Sunshine and Fresh Air. Germs and Dirt and 
Darkness must flee. 


so he can have the sign put on the house. Where is your tele¬ 
phone? 

Mother. Elizabeth, show the doctor the telephone. (Exit 
doctor and Elizabeth.) 

Mother. Oh, dear, to think we have to be quarantined for 
so long! 

Enter Dr. Quack 

Dr. Quack. Have some more medicine, 99 cents. Finest on the 
market! Do have some more! (Pushed out of room by Sunshine 
and Fresh Air.) 

Enter Dr. Payne 

Dr. Payne. I suppose you know it is quite necessary that you 
obey the quarantine laws. 

Mother. What are those laws, anyway? I’ve never paid much 
attention to them. 

Dr. Payne. Then I must read them to you. (Reads) “Whenever 
a communicable disease that is quarantinable exists in any 
premises, the entire building is to be placed under quarantine. 
Smallpox, diphtheria, scarlet fever, and influenza must be 









126 


HYGIENE BY EXPERIMENT 


quarantined. Whenever the head of the family desires to be 
quarantined out and is willing to render to the public as much 
protection as possible, the person then may be given an anti¬ 
septic bath, put on clothing that has been fumigated, and then 
be turned out.” ( While Dr. Payne reads , Elizabeth tips over basket. 
The mother , in correcting her and picking up the scattered things , 
pays no attention to the reading of the last part of the law.) 

Dr. Payne. Are you quite sure you understand these laws 
now? 

Mother. Oh, yes! I always did know all of that. 

Dr. Payne. Well, I must be going. Be a good girl, Elizabeth, 
and get plenty of Sunshine and Fresh Air, so you’ll not take sick 
like Helen. I will have this prescription filled for you. Goodby. 
I shall call again tomorrow. {Exit.) 

Mother. It does seem a shame that we have to be quarantined. 
What will father and Ned do for a place to stay? And they must 
keep working, for we do need the money. 

Elizabeth. Oh, here they come now! 

Enter father and Ned 

Mother. Did you see that horrid sign on the door? 

Father. Yes. What does it all mean? 

Mother. It means that we must stay quarantined until Helen 
is entirely well, and that may be a month. 

Ned. Well, we can’t stay here all of that time. I can’t give up 
my job for the sake of an old card on our house. 

Mother. Well, then, what shall we do? 

Father. I see no reason why we can’t go back and forth. No 
one will be the wiser if we leave before the neighbors are up, and 
remain away until dark. 

Elizabeth. Oh, no, that wouldn’t be right. Miss Smith, at 
school, says that where there is a red card on your house no one 
should leave unless he has been fumigated. 

Mother. What difference would that make if no one knew? 

Ned. Sis is right, mother. If we went back and forth we could 
carry these germs to some one else, even though we didn’t get 
the scarlet fever ourselves. 

Elizabeth. And other little girls might get sick like Helen. 

Father. Yes, we must not be the ones to spread this contagious 
disease any further. That is probably how Helen caught it — 


DISEASES CAUSED BY BACTERIA 


127 


through some one’s carelessness and wrongdoing. I’ll call Dr. 
Payne. Perhaps he can tell us something to do. {Goes out to 
telephone.) 

Mother. Helen, it is time for you to take some more medicine. 

Enter father 

Father. Dr. Payne says he will be right down and will fumigate 
Ned’s clothing and mine, and tell us what to do. 

First Germ {frightened). Fumigate! That means the end of us 

here. 

Second Germ. I am beginning to feel sick already. 

Third Germ. Let’s stick as long as we can. Don’t give up so 
soon. 

Enter Dr. Payne 

Dr. Payne. Well, I thought we could fix it it up so you could 
keep on with your work. 

Father. Yes, we must do that, by all means. 

Dr. Payne. Now get the clothes you will need and we will go 
into the kitchen and fumigate them. You had better tell your 
wife and children goodby, also; for you will not be allowed to come 
back into this room for a good while. {Father and Ned get clothes.) 

Father. Goodby, Elizabeth. Be a good girl and mind your 
mother. 

Mother. But what shall we do for the things we’ll need? 

Father. I will have the milkman leave milk for you and I will 
also order groceries for you every day. Now don’t worry and 
everything will come out all right. Helen, take your medicine 
and do what Dr. Payne says, so you will soon be well again. 
Goodby. {Exit father , Ned and Dr. Payne.) 

Elizabeth {running to door). Goodby, Daddy. 

Mother {weeping). Oh, dear me! What shall I do? 

Elizabeth. Don’t cry, mother. Helen will soon be over her 
illness. 

Mother. Well, I suppose I should make the best of it and keep 
cheerful. 

Sunshine. How nice it will be when we get rid of these germs. 
We can now see our way through. I shall call on my Sunbeams, 
and this child will soon be well. 

Fresh Air. Yes, if people only realized what a help we are to 
them they would have more respect for us. 


128 


HYGIENE BY EXPERIMENT 


Helen. I feel so much better; that fresh air feels so good, and 
my headache is almost gone. 

Mother. Do you, dear? I am so glad, for it will not be long 
then before we can fumigate the place and have father and Ned 
come home. 

Elizabeth. Oh, goody! Let’s fumigate now!! 

Exercise II. Questions for Investigation 

1. The pus-forming bacteria. 

A. What are the names of some of the different 
pus-forming bacteria? 

B. What are some of the diseases they cause? 

C. How should wounds be cared for? 

D. Why are pus-forming bacteria injurious to the 
body? 

E. How can one be protected against pus-forming 
bacteria? 

2. Tetanus, or lockjaw. 

A. How are tetanus bacteria different from most of 
the other bacteria? 

B. Where are they found in nature? 

C. How do they get into the body? 

D. Do the germs directly destroy the cells of the 
body, or do they make a poison that stops the work of 
the cells? 

E. What is a “gas bacillus”? 

3. Diphtheria. 

A. What is the shape of a diphtheria germ? 

B. How do diphtheria germs get into the body? 

C. Why are they so hard to control? 

D. Do diphtheria germs cause injury to the body in 
the way that tetanus germs do or in the way that pus¬ 
forming germs do? 


DISEASES CAUSED BY BACTERIA 


129 


E. Can you prepare a dramatization of the preparation 
of diphtheria antitoxin? 

4. Pneumonia. 

A . What parts of the body are affected by pneumonia? 

B. What are the two different ways in which the 
disease may cause death? 

C. How do the germs get into the body? 

D. How can some forms of pneumonia be prevented? 

E. What are the four different kinds of pneumonia 
germs? 

5. Influenza, whooping cough, and colds. 

A . What is influenza 

B. How can you guard against influenza? 

C. What is whooping cough? 

D. Why should cases of whooping cough be quar¬ 
antined? 

E. What is the shape of the germs that cause colds? 

F. Why should colds be avoided? 

G. When you have a cold, what should you do? 

6. Tuberculosis. 

A. How old is this disease among men? 

B. What is the shape of the germ? 

C. Who was Dr. Koch? 

D. Who was Dr. Trudeau? 

E. What is the most common form of tuberculosis? 

F. How are the germs transmitted from one person 
to another? 

G. Does the germ do its harm by destroying body 
cells, or does it do it by making toxins? 

IT. What animals have tuberculosis? 

I. Why should you use milk only from cows that have 
passed a tuberculin test? 

J. How can tuberculosis be prevented? 


130 


HYGIENE BY EXPERIMENT 


K. Dramatize the care of a consumptive patient. 

7. Typhoid fever. 

A. What is the shape of the typhoid-fever germ? 

B. How may the germ be transmitted? 

C. In what part of the body does the germ do its work? 

D. How can the disease be prevented? 

8. Some relatives of the typhoid germ. 

A. Where does the colon bacillus live? 

B. What is acute dysentery? 

C. What causes diarrhea? 

D. What causes summer complaint? 

9. Meningitis. 

A. Is there only one kind of germ producing this 
disease? 

B. How is infectious meningitis caught? 

C. How can it be cured? 

10. Some other bacterial diseases. 

A. What kind of germ causes sore eyes? 

B. What causes acute rheumatism? 

C. What kind of germ causes leprosy? 

D. What kind of germ causes cholera? 

E. What kind of germ causes mumps? 

F. Do plants ever have germ diseases? 

G. Do lower animals ever have germ diseases? 


STUDY TWENTY 

DISEASES DUE TO PLANTS OTHER THAN BACTERIA 

Some people are troubled with a disease called hay 
fever. Perhaps you wonder why the word “hay” is used to 
describe the fever. You will have a chance to suggest a 
better name for this disease after you have found out 
more about it. It is different from any other disease we 
have studied so far, for it is one of a group of diseases 
due to the growth of plants in the body. These plants 
are of higher form than the one-celled plants we have 
been studying under the name of bacteria. They belong 
to the group of many-celled plants, a very few of which 
have the strange life habit of growing, at least in part, in 
the human body. 

Exercise I. Many-Celled Plants That Grow in Part 

in the Human Body 

i. Examining pollen grains. Take any freshly bloom¬ 
ing plant and note the pollen on the ends of the stamens. 
Put some of the pollen grains under a compound micro¬ 
scope and study them. 

A. Do pollen grains from the stamens of a single 
flower differ much? • 

B. Look at the pollen grains from another kind of 
flower. Are they the same in shape as the pollen grains 
of the first flower? 

C. Now, with your simple microscope, look at the end 
of the pistil, the little stem in the very middle of the 
flower. Sometimes there are several pistils, but they 
always look different from the stamens. The pollen 
grains fall on the end of a pistil and then grows a little 
tube down through the pistil where the nucleus of the 


132 


HYGIENE BY EXPERIMENT 



Fig. 36. A bad living place for any one susceptible to hay fever. In 
the foreground is a mass of ragweed headed out and loaded with its 
trouble-making pollen. 


pollen grain helps to make seed. How does the end of 
the pistil resemble, if at all, the inner surface of the nose? 

2. Finding out about hay fever. Read about this 
disease in any recent health book or encyclopedia. 

A. What is the cause of hay fever? 

B. Where does the disease take hold? 

C. Why do hay-fever patients often go to the moun¬ 
tains or lakes in midsummer? 

D. What is the new remedy or preventive for hay 
fever that helps some people? 

E. What are some of the plants whose pollen produces 
hay fever? 

F. What could be done so that nobody would have 
hay fever? 

G. What would be a better name than hay fever for 
this disease? 











DISEASES DUE TO PLANTS 


133 


3. Studying the mold. Somewhat different are those 
diseases in which a whole plant grows in the human 
body, instead of only a part of it as in hay fever. Before 
you study any plant diseases of this class, you will need 
to make a little study of that group of fungous plants 
known as molds. For your study you will need a slice 
of raw white potato or fresh bread. This will have to 
be kept in any rather warm and moist dark place, for a 
day or two. Numerous fine white threads will now 
appear. After a little, the mold will turn somewhat 
darker, as it will develop numerous black seedlike spores. 
Examine some mold with either a simple or compound 
microscope. Record here what you have learned. 
What does a specimen of common mold look like under 
a microscope? 

Exercise II. Questions for Investigation 

(Consult Ritchie’s Primer of Sanitation or a large 
dictionary or any encyclopedia.) 

1. Ringworm. 

A. What are three different places in which ringworm 
attacks the human skin? 

B. Why has the disease been called ringworm? 

C. Is this disease contagious? 

2. False tuberculosis. 

A . What kind of plant is nocardia? 

B. Where does it sometimes grow in the human body? 

3. Tetter, barber’s itch, and thrush. 

A. What information about these diseases do you 
succeed in finding? 

4. Poison ivy. (This plant does not grow in the body. 
It is mentioned here because it is responsible for a 
disagreeable skin poisoning.) 


134 


HYGIENE BY EXPERIMENT 


A. What is the cause of ivy poisoning? 

B. How can you tell a poison-ivy plant by the leaves? 

C. What is the first thing that should be done in a 
case of ivy poisoning? 

5. Concluding studies. 

A. Set down in your notebook the names of any 
other diseases that you may learn are due to plants. 

B. What health habits will help to guard against 
diseases such as those you have been considering? 


STUDY TWENTY-ONE 

DISEASES CAUSED BY PROTOZOA 

In Study Sixteen you learned something about the 
tiny animals called protozoa. These are the simplest 
and it is believed that they were the earliest of all 
animal forms. Just why they should be classed as 
animals rather than plants is a nice question about 
which we do not need to bother at this time. Indeed, 
the scientists have enough to do to distinguish between 
the simplest forms of life, and sometimes even they 
cannot definitely classify particular germs as animals or 
plants. In this Study you are to consider a few of the 
disease-producing animal germs, or protozoa; and you 
may, if you choose, dramatize some of the methods of 
caring for persons afflicted with protozoan diseases. 

Exercise I. Diseases Caused by Protozoa 

For information study other textbooks, pamphlets, 
or encyclopedias. 

i. Malarial fever. After studying carefully Fig. 37, 
record answers in your notebook to the first nine questions 
that follow: 

A. What is the shape of a malaria microbe? 

B. Where does the germ get its nourishment while 
living in the human body? 

C. After the germ has quit its growth in the human 
body, where must it go next in order to complete its 
growth, and how does it get there? 

D. Into what two distinct forms or shapes do the 
germs develop in the new host? 

E. Form No. 9 is a female germ and forms No. 9 a 
and 9 b are males. What is happening in form No. 10, 

i35 


136 


HYGIENE BY EXPERIMENT 


and in what part of the mosquito’s body does this take 
place ? 

F. Where does the resulting form, No. II, now go? 



Lenckhart-Chun 


Fig. 37. The malaria germ and its mosquito carrier. 
The mosquito could get along very well without the 
germ, but the germ could not exist if the mosquito were 
exterminated. Human beings could get along much 
better without either the mosquito or the germ. 


G. Which sex of the mosquito is the one that carries 
malaria germs to man? 












DISEASES CAUSED BY PROTOZOA 


137 

H. How could you keep a human malarial patient 
from giving malaria germs to some one else? 

The answers to the questions immediately following 
are to be sought for in other books and pamphlets. 

I. What did General Gorgas do to show how malarial 
fever can be controlled? 

J. To what parts of the human body does the malaria 
germ do its damage? 

K. What makes one have a chill when suffering with 
malaria? 

L. What medicine is used to prevent and check this 
disease ? 

M. In what three ways can malaria fever be prevented? 

2. Yellow fever. 

A. How is yellow fever caught? 

B. What did Dr. Walter Reed do to help find out the 
cause of yellow fever? 

C. How may yellow fever be prevented? 

3. Measles. 

A. What is meant by the “incubation period” in a 
disease ? 

B. Why should measles be quarantined? 

C. Is it really desirable, as people sometimes say, that 
“boys and girls should have the measles while they are 
young”? 

4. Smallpox. 

A. What is the cause of smallpox? 

B. Has this disease been the cause of many deaths? 

C. How is smallpox spread? 

D. How does the process of vaccination serve to get 
more opsonin into the blood? 

E. How do you know that vaccination is really 

valuable? 

* 


138 HYGIENE BY EXPERIMENT 

F. What did Edward Jenner do for humanity? 

G. What is your plan for dramatizing the process of 
vaccination? 

5. Rabies, or hydrophobia. (See Farmers’ Bulletin 
No. 149.) 

A. To what is hydrophobia due? 

B. How could the country be freed from this disease? 

C. Why should one avoid being scratched or bitten 
by a mad dog? 

D. Why is the word “hydrophobia” not a good name 
for this disease? 

E. Dramatize the Pasteur treatment for rabies. 

6. Other protozoan diseases. 

A. What is the difference in the causes of acute and 
of chronic dysentery? 

B. What is chicken pox? 

C. What is scarlet fever? 

D. What is pyorrhea, or Riggs’ disease? 

E. What lower animals suffer from the effects of 
protozoan diseases? 


STUDY TWENTY-TWO 

DISEASES DUE TO SIMPLE ANIMALS OTHER THAN 

PROTOZOA 

Did you ever hear of measly pork? If you could 
secure a very thin slice of such pork mounted on a 
microscopic slide, and could then examine it under even 
a simple microscope, you would see very tiny wormlike 
creatures coiled up here and there within it. Measly 
pork illustrates a case of diseased flesh due to the action 
of animals of a higher order than the Protozoa; that is, 
many-celled animals. 

You will recall that the Protozoa are one-celled animals. 
Most animals are made up of many cells, and these are 
called Metazoa. It has been estimated that the human 
body is made up of four hundred trillion cells. But 
there are simple metazoans made up of a comparatively 
few cells. Some of these make trouble for human beings. 
What a few of these trouble makers look like, you will 
find out in the study that follows. 

Exercise I. Questions for Investigation 

i. Hookworms. Examine with a simple microscope 
p r eserved specimens of hookworms, if these can be 
obtained. 

A. In your notebook make a picture of a hookworm. 

B. Why, do you think, the hookworm was given the 
name it goes by? 

C. How do hoqkworms get into the body? 

D. How does hookworm disease affect the sufferer? 

E. In what part of the United States is the hookworm 
disease most common? 

F. In what two ways can hookworm disease be 
prevented ? 


i39 


140 


HYGIENE BY EXPERIMENT 


2. Trichina. Examine with a simple magnifying glass 
a mounting of a trichina worm as it lies buried in a thin 



Fig. 38. One of the metazoa (a metazoon), greatly magnified. This worm, 
imbedded in a human muscle, is a trichina (tri-ki'na). Trichinae are 
most commonly found in swine. At the great packing establishments 
the pork is inspected for trichinae as well as for tuberculosis and cholera. 
Thorough cooking of any meat will kill the ringworms. 


slice of pork. If a real specimen cannot be had, be sure 
to study Figure 38 carefully. 

A. Make a little picture of a trichina worm in your 
notebook. 

B. Write briefly in your notebook the life story of a 
trichina worm. 

C. What is the name of the disease caused by trichina 
worms? 

3. Eelworms. From a neighborhood doctor secure, if 
you can, a bottle containing a few specimens of intestinal 
worms. 

A. In your notebook make a sketch showing the 
actual size and shape of these worms. 

B. What part of the body do eelworms infest? 

C. How do eelworms get a start in the human body? 















DISEASES DUE TO SIMPLE ANIMALS 


141 

D. What effects do eelworms produce when they once 
get a start in the human body? 

4. Pinworms. Examine a few preserved specimens of 
pinworms, if they can be secured. 

A. What is the appearance of a pinworm? 

B. In what part of the human body are pinworms 
sometimes found? 

C. How do pinworms get into the body? 

5. Whipworms. Examine a preserved specimen of 
whipworm, if you can get one. 

A. What is the appearance of a whipworm? 

B. In what countries is whipworm disease most 
common? 

6. Filaria worms. (See Ritchie’s Primer of Sanita¬ 
tion.) 

A. Copy in your notebook a little picture of a filaria 
worm. 

B. What disease does the filaria worm cause in man? 

C. In what countries is this disease common? 

D. What insect often carries the germ of this disease 
to man? 

7. What health habits can you suggest to help guard 
against the various worm diseases? 

8 . Write in your notebook the names of any other 
diseases that you may learn are due to simple animals 
besides Protozoa. 


STUDY TWENTY-THREE 

MOSQUITOES AS CARRIERS OF GERMS 

In former times frightful stories were told and believed 
about dragons. The dragons were said to infest swamps, 
from which they would rise to spread death among the 
people of the land. There was a greater basis of truth 
for these old stories than one would at first think; but 
the spreaders of death were the mosquitoes that rose 
from the swamps. The mosquitoes, carrying the germs 
of fever, were far more deadly than a monster such as was 
imagined could have been. A monster might have been 
fought, but the mosquito was not even known to be the 
real enemy. Because his ways have not been understood, 
the mosquito has long been one of the most successful 
enemies of mankind. You already know of three diseases 
it carries. Since we now understand the menace of the 
mosquito, it becomes our problem to get rid of it. In 
the present Study we shall consider methods of mosquito 
control. Farmers’ Bulletins Nos. 444 and 445 will come 
in helpfully here. 

Exercise I. The Life History of a Mosquito 

1. Two kinds of mosquito wigglers. Some time in 
warm weather, when ponds or rain barrels abound with 
wigglers, provide yourself with a glass of water containing 
wigglers. Make a study of the different kinds of wigglers 
to be found in the water. In general, two kinds should be 
found, a longer sort, the larvae (singular, larva), and a 
coiled-up sort, the pupae (singular, pupa). What are 
wigglers? Have you found two kinds? Where did you 
get the water containing them? 

2. Examining mosquito larvae. Select a number of the 


142 


MOSQUITOES AS CARRIERS OF GERMS 


H 3 



Fig. 39. The members of this class have provided themselves with 
mosquito “aquariums.” The wigglers in these jars will not be allowed to 
wiggle any more when the study is over. 


longer wigglers, the larvae, and put them into a small 
bottle or test tube of clear water. If the locality is very 
malarial, it is possible that two kinds of these longer sorts 
can be found. The larva of the common mosquito ( Culex ) 
has a bigger head than other mosquitoes, is more lively, 
and stays under water more to feed; and when it comes 
to the surface to breathe, it hangs with its head down. 
The larva of the malaria mosquito {Anopheles) has a 
head only a little larger in diameter than the body, is 
less active than the larva of the common mosquito, and 
lies horizontally at the surface most of the time, both to 
feed and to breathe. What have you learned through 
observation about the behavior of the common mosquito 
and perhaps of the malaria mosquito in the larval state? 

3. A larva under a microscope. Now take a specimen 
of the larva of the common mosquito and a specimen of 
the larva of the malaria mosquito, if you have found it. 
Place each of these in a drop of water on a piece of glass. 
Study with a simple microscope, looking to find the parts 








144 


HYGIENE BY EXPERIMENT 



Fig. 40. Wiggler: the larva of the common mosquito. The half-tone 
cut was made from a photograph of a large glass model of the larva. 
The model is in the American Museum of Natural History in New York. 

shown in the pictures in the Farmers’ Bulletins on 
mosquitoes. Observe especially the differences between 
the larvae of the common and of the malarial types of 
mosquitoes. Study Figure 40. 

A. In your notebook make a drawing of a mosquito 
larva. 

B. What differences did you find between the larvae 
of the common and of the malaria mosquito? 

4. Examining mosquito pupae. Select from your 
original supply of wigglers a number of the coiled-up 
sort, the pupae , and put them in a small bottle or test 
tube of clear water. Again look for the two sorts, common 
and malaria, the former lying the more nearly vertical 
and being the more coiled. Experiment with these 
pupae to find how they behave differently from larvae. 

A. In your notebook make a sketch of a mosquito 
pupa. 

B. How do mosquito pupae behave as compared with 
mosquito larvae? (See Figure 41.) 

5. Seeing a pupa under a microscope. Make use of a 
simple microscope in examining specimens of pupae, just 




MOSQUITOES 45 CARRIERS OF GERMS 


145 


as you did with the larvae. 

How do pupae differ from 
larvae in appearance? 

6. Capturing an imago. 

Set in a warm place the 
glass in which you had 
your original collection of 
wigglers and place a piece 
of glass or mosquito 
screening over the vessel. 

Examine the vessel the 
next day to see if adult 
mosquitoes, or imagoes , 
have appeared above the surface of the water. How do 
you know that adult mosquitoes come from mosquito 
larvae ? 

7. Destroying baby mosquitoes. Take another vessel 
with wigglers, and pour into it enough kerosene to make 
a thin film over the water. Then cover the vessel with a 
piece of glass or mosquito screening. 

A. Do any imagoes appear above the surface of the 
water after you put kerosene on it? 

B. What do you think has happened to the wigglers 
and why? 

C. What is one way to get rid of mosquitoes in a rain 
barrel or pond? 

8. Fish as enemies of baby mosquitoes. Into a third 
glass of water with wigglers in it, put a goldfish or min¬ 
now and see what happens. 

A. What reason have you for believing that fish are 
enemies of mosquitoes? 

B. What is another good way to help get rid of 
mosquitoes? 



Fig. 41. Wiggler: the pupa of the 
common mosquito. This illustration 
also is from a glass model in the 
American Museum. 




146 


HYGIENE BY EXPERIMENT 


9. Distinguishing male from female mosquitoes. 

Examine adult mosquitoes with the naked eye or with 
the simple microscope to distinguish males from females. 
The males have feathery hairs, or antennae, between the 
eyes, and the females have hairs that are not feathery. 
(See Number 14 in Figure 37.) It is the female Anopheles 
mosquitoes that carry malaria germs. What difference 
have you seen between a male and a female mosquito? 

10. An imago under a microscope. Study an imago 
with a simple magnifying glass and find the answers to 
the questions that follow. 

A. How many legs and wings has an adult mosquito? 

B. When a mosquito is at rest, on how many legs 
does it stand? 

C. What is the difference in the way a common 
mosquito and a malaria mosquito stand? 

D. How many parts are there to the body of a mos¬ 
quito? 

11. The four stages in the life of a mosquito. To 

make the life story of the mosquito complete, you have 
yet to examine a mosquito’s eggs. These may be found 
floating on the surface of quiet water in warm weather. 
The eggs of a mosquito are no longer than a pin is wide, 
and only one fifth as wide as they are long. They stick 
together to make a little raft, if they are from the common 
mosquito; but they lie alongside each other if they are 
from the malaria mosquito. What are the four stages in 
the life history of a mosquito? 

12. Raising a brood of mosquitoes. A good way to 
learn the complete life history of the mosquito is to take 
one of the egg masses you found and keep it in a glass 
of water in a warm place, looking at the glass now and 
then to note the four successive stages of the mosquito’s 


MOSQUITOES CARRIERS OF GERMS 


147 


life. The water in the glass should have a thin scum, 
on which the eggs float lightly. If kept under water 
they will “drown,” for they are meant to stay on water, 
much as a needle may be made to float on water. 

A. How long does it take to develop mature mos¬ 
quitoes from eggs? 

B. Why do more mosquitoes come from quiet ponds 
than from wind-blown lakes? 

Exercise II. Questions on the Foregoing Exercises 

1. Why do wigglers keep coming to the top of the 
water so often? 

2. How does a wiggler get its air? 

3. Why did the wigglers die in the water that had oil 
on top of it? 

4. What do wigglers live on? 

5. What does the imago live on ? 

6. What are some ways to get rid of mosquitoes? 

Exercise III. Questions for Investigation 

1. How do mosquitoes live through the winter? 

2. Why should a person sick with malaria or yellow 
fever be kept screened? 

3. What did General Gorgas do to drive malaria fever 
from the Panama Canal Zone? • 

4. What sanitary practices do you suggest in dealing 
with mosquitoes? 


STUDY TWENTY-FOUR 

FLIES AS CARRIERS OF GERMS 

What are the most dangerous animals in the world? 
Lions? Tigers? Cobras? Tarantulas? No, you have 
another guess to make. Flies, flies, flies! These are the 
most dangerous animals in the world, for they are 
carriers of more disease germs than are any other 
creatures. In addition to being so dangerous to health, 
flies are a nuisance in many ways. You should learn 
all you can about them so you can help the more effec¬ 
tively to get rid of them. Farmers’ Bulletins Nos. 734, 
851, and 1097 will give you a great deal of information. 

Exercise I. Studying the Adult House Fly 

1. The upper side of a fly. Catch a house fly and kill it 
with a drop of gasoline. Mount it on a small white card 



Fig. 42. Louis Agassiz, the great naturalist, used to tell his students 
over and over again, “Study your fish!” When all had studied their fish, 
Agassiz would teach them what they had been unable to learn for 
themselves. The students shown here are beginning a study of the fly in 
the right way, by examining specimens mounted on white paper. 

148 












FLIES AS CARRIERS OF GERMS 


149 


by running a pin through the thick part of its body. 
Using the pin as a handle, make an examination of the 
fly’s upper parts with the naked eye and also with a 
simple microscope. Note the shape of the head, the big 
compound eyes, and the narrow neck. Look for the 
featherlike hairs between the eyes. Count the black 
stripes on the back of the fly, for no other kinds of flies 
are marked exactly as the house fly is. See if there are 
hairs on the back also. Look for the marks of veins on 
the wings and especially the veins at the rear, next to 
the inside, and in each wing note the knee-shaped bend 
of this vein. Only house flies have these veins bent so. 
Pull the wings off and see the little knob-ended balancers 
just back of the place where the big wings are fastened 
to the body. These balancers are all that are left of a 
second pair of wings that flies had, long, long ago. 
What are five or more facts you have found out by 
studying the upper side of a house fly? 

2. The underside of a fly. Mount another specimen 
of a house fly, pinning it back-down to the card. Note 
that the body is made up of three main parts, the head, 
the thorax, and the abdomen. With a simple microscope 
observe the proboscis of the fly, and the parts of the face. 
With a very strong magnifying glass, look at the feet, 
noting the fine hairs that have some sticky stuff on them. 

A. Do you think the house fly bites, or does it merely 
suck its food with its proboscis? 

B. Are there hairs around the mouth? 

C. How many pairs of legs has a fly? Any insect? 

D. To which part of the body are the legs fastened? 

E. Are there hairs at the back of the hindmost pair of 
legs? If so, then you may be sure you are studying a 
house fly, for other flies do not have these hairs. 


150 


HYGIENE BY EXPERIMENT 



Fig. 43. The common house fly. This cut also is made from a photograph 
of a very large model in the American Museum of Natural History. 


F. On what part of the abdomen do you find hairs? 

G. How are flies able to walk on walls and ceilings; 
as you judge from examining their feet? 

3. Various kinds of flies. Examine a few other kinds of 
flies, if you can get specimens, such as the stable fly, 
blowfly, horse fly, and botfly, and see how each differs 
in appearance from a house fly. Particularly, make a 
close examination of a stable fly’s mouth. 

A. Does a stable fly bite or does it suck its food? 

B. When a fly bites you, can it be a house fly? 

C. How does a blowfly, either blue or green, differ 
from a house fly? 

D. How does a horse fly differ from a house fly? 

E. How does a botfly differ from a house fly? 







FLIES AS CARRIERS OF GERMS 


151 

4. The behavior of flies. Collect a few flies in a small 
screen flytrap and study their movements for a while. 

A. Why does a fly rub its feet together every now 
and then? 

B. Which way does a fly do the most walking on the 
side of the trap, up or down? 

C. Why is a flytrap usually made to let the flies in 
at the bottom instead of at the top? 

D. If you make one side of the trap dark and the 
other side not so dark, on which side do you find the 
flies collecting? 

E. If you make one side of the trap very bright and 
the other not so bright, on which side do the flies prefer 
to collect? 

F. Judging from your experiments, what degree of 
light do flies prefer? 

G. Why do you think flies in a darkened room seek 
streaks of light at the windows? 

H. By what sense (sight, hearing, or smell) do flies 
find food, as you judge from putting a thin cloth on 
one side of a fly cage and then bringing food near that 
side of the cage? 

5. Flies as germ carriers. After recalling the experi¬ 
ment in which you caused a fly to walk over a germ 
garden, what do you know of a fly’s ability to carry 
germs? 

Exercise II. The Life Story of a Fly 

I. The egg stage. Do you think gnats are only baby 
flies, or do you think flies develop from something else 
than gnats? You can find out for yourself. Put a piece 
of fresh meat out of doors for blowflies until a deposit 
of the flies’ eggs is found on it. In the bottom of a 
drinking glass put a piece of moist cloth. Fill the glass 


152 


HYGIENE BY EXPERIMENT 


two thirds full of bran or breakfast food, and place the 
piece of fly-blown meat on the bran or breakfast food. 
After covering the glass with fly screening, set it aside in 
a warm place. 

The egg stage is, of course, the first stage in the life 
history of a fly. Carefully examine a fly’s egg with a 
simple microscope. What have you learned about the 
appearance of the egg of a fly? 

2. The larval stage. The second stage of a fly’s life 
comes after about a day, when the eggs are hatched out. 
This is the maggot, or larval stage, and it lasts about a 
week. Examine the development of the maggots from 
day to day, being careful to keep the cloth in the bottom 
of the glass moist. How many times is the grown maggot 
larger than the egg? 

A. Just how many days was it until your larvae, or 
maggots, quit eating and began to go into the next stage? 

3. The pupal stage. After the maggots are full- 
grown, they will pass to the bottom of the glass to enter 
their third or pupal stage. They are now called pupae 
(singular, pupa ) and look like small, imperfect grains of 
wheat. They will remain seemingly quiet for nearly 
another week. Supplement the study of this stage, 
if you can, by digging into the bottom of a pile of horse 
manure and finding there a quantity of pupae. 

A. What is a pupa? 

B. Of what color is a pupa? 

C. Will a pupa move if you touch it? 

D. Where are most house flies hatched? 

E. What would be one good way to reduce the number 
of flies in a neighborhood? 

4. The imago stage. If all has gone well, the adult 
fly or imago should appear in your breeding glass after 


FLIES AS CARRIERS OF GERMS 


153 


about a week of the larval stage. Be very careful to 
keep the screen on the glass at this time. 

A. Just how long did your flies continue in the pupal 
stage ? 

B. How does the size of the body of an imago compare 
with that of a full-grown maggot? 

C. What are the four stages in the life history of a fly? 

D. How long altogether did it take your flies to 
develop? 

Exercise III. Getting People Interested in a Fly-Free 

Community 

For about fifty cents there can be had of the Inter¬ 
national Harvester Company, Chicago, Illinois, a set of 
fourteen stencils for making fly charts. These stencil 
sheets, which are about 30 by 45 inches in size, give a 
lot of information about flies. With these in hand, the 
outlines of charts can be made on suitable paper; but 
the stencil marks will need to be touched up with colored 
pencils. The chart making may well be divided up among 
the members of the hygiene class. 

When the charts are all completed, they should be 
mounted on a stand or hung against the wall. Then on 
some Friday afternoon you and the other pupils may give 
talks on flies to school visitors whom the teacher and 
you have invited. Let each pupil select one of the charts 
and with it make a four-minute talk. The teacher will 
be able to provide each pupil with one or more pamphlets 
about flies, from which his little speech can be made up. 
Indeed, you can find speeches already prepared in the 
little book the International Harvester Company sends 
out with the stencils. By putting on a good program, 
which may well contain exercises besides those on flies, 


I S4 HYGIENE B Y EXPERIMENT 

N 

you can help to make your community better informed 
on the fly question and thus better able to guard its 
health. 

1. What have you done to help establish a fly-free 
community? 

2. What reason have you for thinking you have had 
some success? 

Exercise IV. Questions for Investigation 

i Are flies ever really useful? 

2. How do flies differ from other insects in the number 
of their wings? 

3. In what two very different ways may flies carry 
germs? 

4. About how many germs does an average fly carry 
on its body? 

5. Why is it not well to have flies alighting on the food 
you eat? 

6. For what two reasons is it not wise to have flies 
around a sick person? 

7. Why should houses be screened in summer? 

8. How can a flytrap be rigged up in a stable window 
so as to clear the stable of flies? 

9. What is really the most effective way to get rid of 
flies in a neighborhood? 

10. What are four practical ways to get rid of adult 
flies about your own house? 

11. Why is typhoid fever more common in the country 
than in the city? 

12. What germs besides those of typhoid fever may 
flies carry? 

13. What are some good rules of sanitation regarding 
flies? 


STUDY TWENTY-FIVE 

QUADRUPEDS AS DISEASE CARRIERS 

Somebody has calculated that there is a rat for every 
man, woman, and child in the world. Think how much 
waste of food, destruction of property, and transmission 
of diseases is due to vermin such as these! Next in 
importance to the campaign for ridding a neighborhood 
of flies comes that for ridding it of rats. Other germ 
carriers among quadrupeds are but little less important 
to know about and to control. Farmers’ Bulletins 740, 
754 * 78i, 896, 897, and 1069 will supply valuable informa¬ 
tion concerning some of these. See also “The Rat, a 
Sanitary Menace,” a pamphlet issued by the United 
States Health■ Service; and “The Domestic Cat,” Eco- 



Fig. 44. This dog and her puppies are friendly enough, but they may 
assist in the spread of disease. If you have a pet dog, you should keep 
it clean and free from vermin; and at times it may be your duty to keep 
it muzzled. 


155 









HYGIENE BY EXPERIMENT 


156 

nomic Bulletin No. 2, issued by the State Board of 
Agriculture, Boston, Massachusetts. 

Exercise I. Dogs and Cats 

1. Dogs as disease carriers. From what you know of 

dogs, answer the questions that follow. 

A . How may dogs become carriers of disease ? 

B. What insects may dogs carry? 

C. Of what use, if any, are dogs around a house? 

D. Of what use around a farm? In town? 

E. If dogs are to be kept, what precautions should be 
taken to prevent them from becoming a health menace? 

2. Cats as disease carriers. From what you know of 
cats or can learn from the Economic Bulletin referred to 
above, answer the questions that follow. 

A . What habits of cats make them possible carriers of 
disease germs? 

B. If a cat is a really useful animal, what are some of 

its uses? 

C. If a cat is to be kept as a pet, what care should be 
taken to prevent it from becoming a disease carrier? 

D. Why should you not allow a cat to lick a sore? 

Exercise II. Rats and Mice 

1. Rats as disease carriers. From what you know of 
rats, and from the U. S. Health Service pamphlets 
referred to above, record answers to the questions that 
follow: 

A. What is the food of a rat? 

B. What habits of rats make them particularly 
undesirable about a dwelling house? 

C. How can rats become carriers of disease? 

D. What are some disease germs that rats carry? 


QUADRUPEDS 45 DISEASE CARRIERS 


157 



Fig. 45. These fine-looking Jersey cattle seemed to be healthy, but the 
tuberculin test showed that most of them were affected with tuber¬ 
culosis. The national government and our state governments are 
doing a great deal to protect people from diseased meat and infected milk. 

E. How can a place be freed from the rat pest? 

2. A mouse. If your teacher thinks it well to do so, 
you may make some simple studies of a live mouse in a 
cage. However, perhaps you already know enough 
about the habits of a mouse to be able to answer the 
questions that follow 

A. What do mice eat? 

B. How can they be carriers of disease? 

C. What are some disease germs they may carry? 

D. What reasons are there for ridding a house of mice? 

E. How can a home best be freed of mice? 

Exercise III. Cattle and Hogs 

1. Cattle as disease carriers. For studying cattle as 
disease carriers, you should have at hand Farmers’ 
Bulletin No. 1059, and you should also have the bulletins 
issued by your state veterinarian, who may be addressed 
at your state capital. 











158 


HYGIENE BY EXPERIMENT 


A. What common disease does a cow sometimes give 
to people? 

B. How has it been made possible for you to be sure, 
in some of our states, that the milk you drink does not 
contain the germs of this disease? 

C. What do you think of a man who will sell the milk 
or the meat of a cow that he knows is diseased? 

D. In your state whose business is it to find out 
whether a dairyman’s cattle are diseased? 

2. Hogs as disease carriers. Either in city or country 
much can be learned from a visit to a slaughterhouse. 
If you make such an excursion, you should note partic¬ 
ularly whether the meat is handled in such a way as to 
guarantee that it is wholesome when it is placed on 
sale in the meat markets. 

A. What feeding habits of hogs make them easily 
capable of catching disease? 

B. What are two diseases that hogs are particularly 
liable to transmit to human beings? 

C. To what extent is a hog raiser under moral obliga¬ 
tion to see to it that his hogs are free from disease? 

i 

Exercise IV. Questions for Investigation 

1. What disease do dogs sometimes give to people? 

2. Are dogs more beneficial than injurious? 

3. Why should you not fondle a sick cat? 

4. What should be done with a cat that kills birds? 

5. Does a domestic cat do more harm than good? 

6. How much do rats cost America every year? 

7. What disease do fleas help rats to give to man? 

8. What is the work of a veterinarian? 

9. How can he be helpful in maintaining good health 
in a community? 


QUADRUPEDS AS DISEASE CARRIERS 


159 


10. How much money is lost every year in America 
because the cattle herds have not been freed from 
tuberculosis? 

11. How do cattle catch tuberculosis? 

12. What is the tuberculin test for cattle? 

13. What is tuberculin and how is it made? 

14. When a cow has been given an injection of tuber¬ 
culin, how can you tell whether she has tuberculosis? 

15. What is an “accredited” herd of cattle? 

16. How do hogs catch tuberculosis? 

17. What is the tuberculin test for diseased hogs? 

18. Wliat provision has the Government made for 
the inspection of meats? 

19. What disease germ does the tsetse fly carry? 

20. What disease germ does the tick sometimes carry? 

21. List ten diseases that human beings sometimes 
transmit to human beings 

22. What is a “typhoid carrier ,, among men and 
women? 

23. What rules of sanitation should be observed to 
guard against infection from the animals you have 
studied? 


STUDY TWENTY-SIX 


DISPOSAL OF GARBAGE, RUBBISH, AND WASTE 

In the city of Topeka, some years ago, there was a 
campaign to clean up the streets, alleys, and lots of the 
city in order to promote health and comfort and to 
better the appearance of the place. Mr. A. J. McAllister, 
who was then principal of one of the ward schools of 
Topeka, hit upon the idea of having his boys given a 
commission from the health officer to assist in the 
campaign. He divided his ward into smaller districts and 
had groups of boys cooperate with the people in cleaning 
up their premises. The boys courteously suggested to 
the householders the need, if any, for improving the 
appearance of their surroundings and offered to help 
in the work, either for pay or not, as the case seemed to 
justify. A vigorous clean-up contest was developed 
among the various wards of the city, with the result that 
the ward which the boys looked after showed the largest 
improvement in the whole city. The leading Topeka 
paper, you may be sure, had much to say about the 
achievement of the sanitary squad of that ward school. 

Exercise I. Disposal of Rubbish 

The term “rubbish” is here applied to useless materials 
that decay rather slowly, or not at all, as ashes, cinders, 
tin cans, and fragments of old building materials. Since 
rubbish, in addition to being unsightly, will harbor 
vermin, its disposal becomes a matter of vital community 
concern 

The following questions are to be used in a survey you 
are to make around your own home. 

160 


GARBAGE, RUBBISH, AND WASTE 


161 



Fig. 46. A picture was taken of Mr. McAllister’s “Sanitary Squad.” 
but the only copy of it proved unfit for reproduction. So a group of 
boys in the same school posed here to represent the original squad. These 
boys are worthy successors, it is to be hoped, of Mr. McAllister's boys. 


1. What kinds of materials make up most of the 
rubbish around your home? 

2. Is all or part of it regularly thrown into an alley or 
somewhere else off the premises? 

3. Is most of the rubbish thrown freely around on the 
ground near the house? 

4. If thrown about in this way, is there a regular time 
for cleaning it up say once a year? 

5. Is the rubbish ordinarily thrown in a careless heap 
that will harbor vermin? 

6. Is the rubbish kept in boxes, barrels, or other con¬ 
tainers, making the place look neater, but still providing 
a haunt for rats? 

7. Is the rubbish kept regularly in a neat, rat-proof 
place? 

8. By whom and at whose expense is the rubbish 
removed? Can some of it be sold as junk? 

9. What is done with it when it is removed? 






HYGIENE BY EXPERIMENT 


162 


Exercise II. Disposal of Garbage 

Garbage is understood to be the kitchen waste ma¬ 
terial that is likely to decay rapidly. The word is here 
meant to include dishwater and other kitchen waters, 
and the waste material left from preparing meals, as 
well as that left after meals. 

1. Is the garbage at your home, or most of it, thrown 
freely about the place? 

2. Is all or a large part of it kept in barrels or garbage 
cans, to be fed to hogs or other animals? 

3. If a swill barrel or garbage can is used, is it well 
covered so as to keep out flies and other insects? 

4. If the garbage container is well covered, is there a 
large flytrap kept set near it? 

5. If the water is drawn off from the rest of the kitchen 
refuse, what is done with this residue? 

6. Does this residue serve to help breed flies? 

7. Is the residue from the garbage dried and then 
thrown away? 

8. Is it burned in a stove, or in a furnace, or in a 
regular incinerator? 

9. Is it buried and well covered with soil? 

10. Is it fed to chickens or to pigs? 

11. Is it set out to be collected by a garbage man? 

Exercise III. Disposal of Waste 

Pamphlets dealing with the subject of waste disposal 
are to be had of the United States Health Service and 
the United States Department of Agriculture, Washing¬ 
ton, D. C. 

1. Is there an inside toilet in the house where you live? 

2. If so, is it connected with a general city sewage and 
water system? 


GARBAGE, RUBBISH, AND WASTE 163 

3. If thus connected, how is the sewage disposed of 
finally? 

4. If not thus connected, in which of the following 
ways is it treated: 

A. By distribution to a running stream? 

B. By surface distribution? 

C. By subsurface distribution? 

D. By a septic-tank system? 

E. If an outhouse is used, is it over an unprotected 
pit? 

F. Is the outhouse provided with a protected but re¬ 
movable can or box? 

G. If a box is used, are the contents frequently buried? 

H. Is the outhouse stocked with dry earth or slacked 
lime for covering purposes? 

I. Is the outhouse equipped with a septic-tank de¬ 
vice? 

J. Is some other good device used? 

Exercise IV. General Questions 

1. What is the best way to take care of rubbish about 
any home? 

2. What is the best way to take care of garbage about 
any home? 

3. Why should there be the greatest of care in dispos¬ 
ing of human wastes in a sanitary way? How is hook¬ 
worm disease spread? 


STUDY TWENTY-SEVEN 

GOOD WATER FOR DRINKING 

“Water, water, everywhere, 

Nor any drop to drink.” 

This is the cry of the Ancient Mariner in Coleridge’s 
poem; and in all old tales of the sea, the problem of getting 
and keeping a supply of drinking water figures prom¬ 
inently. At first thought it seems curious that seagoing 
vessels should have to carry a supply of water with them. 
But the drinking of sea water, when no fresh water is to 
be had, brings madness first and then death. Sea water, 
however, is not the only water that is unfit to drink. 
Sometimes the clearest-looking fresh water is deadly, for 
it may carry the germs of typhoid fever or germs of other 
diseases, as dysentery. In this Study we shall consider 
methods of getting wholesome water and keeping it fit 
for human use. 

Exercise I. Experimental Studies of Water 

i. Vaporization and boiling point. Pour a pint of water 
into a large tin can that can be securely stoppered, and 
place the can over a burner. Heat till the water boils 
and the can is filled with steam. Determine the temper¬ 
ature of the steam by lowering a dairy thermometer into 
the can. Take the can from the source of heat, stopper 
it quickly and tightly, and then sprinkle cold water over 
the outside of the can, to cool the steam within. Ordi¬ 
narily the can will collapse with weird contortions, owing 
to the removal from the inside of the pressure that bal¬ 
ances the natural pressure of the air on the outside. 

A. What is the temperature of boiling water and 
steam at the altitude where you live? 

164 


GOOD WATER FOR DRINKING 


165 



Fig. 47. An experiment in vaporization. These boys boiled 
a pint of water in the big oil can, and then fastened the screw- 
cap stopper. They have just sprinkled the steam-filled can 
with cold water. See what has happened to the can! 


B. Would this temperature be higher or lower if you 
were to try this experiment at a higher altitude? 

C. What crushed the can down when you poured the 
cold water on it? 

2. Freezing point of water. The freezing point of 
water may be found by taking the temperature of water 
that has plenty of ice floating in it. If possible, a bucket of 
dirty water should be put where it will freeze over. Later, 










HYGIENE BY EXPERIMENT 


166 

the ice can be taken off and some of it melted and poured 
into a clear glass to see if there is any sediment deposited. 

A. What is the freezing temperature of water? 

B. Is the water in ice water as cold as the ice itself? 

C. When water is changed to ice, what seems to be the 
effect on its clearness? 

3. The solvent power of water. Take two glasses of 
clear rain water and dissolve a teaspoonful of salt in one 
of them. Now fill a third glass with water from one of 
the wells in the neighborhood. Allow all three glasses to 
stand in a warm place until their contents dry up. 

A. Was the salt destroyed by being dissolved in your 
glass of water? 

B. Did you get back practically all the salt you put 
into the glass? 

C. How do you know that your sample of well water 
had some substance dissolved in it? 

D. Why can you not tell by merely looking at water 
whether it is good water to drink? 

4. Power to absorb gases. Fill one jelly glass with 
clearwater that has been exposed to the air for some time, 
and fill another glass with water that has just been 
boiled. Into each glass put a bright nail and cover the 
glass with a lid. Examine both nails the next day, re¬ 
membering that iron will not rust unless there is some 
of that part of the air known as oxygen present along 
with moisture. 

A . What is shown by the difference in the appearance 
of the two nails in your experiment as to the amount of 
oxygen in each glass? 

B. What accounts for most of the difference in taste 
between water previously boiled and water not boiled? 

C. Why do fishes in an aquarium stay close to the top 
of the water, if the water has not recently been changed? 


GOOD WATER FOR DRINKING 167 

5. Hard water and soft water. Prepare a soap solution 
by dissolving a small piece of soap in a bottle of hot rain 
water. Provide half a bottle of hard water and half a 
bottle of soft water, put a small quantity of the soap 
solution into each, and shake both thoroughly. Compare 
the contents of the bottles after the shaking. 

A. What do you think makes water hard? 

B. Why is cistern water soft? 

C. Why is soft water more desirable than hard water 
for washing purposes? 

6. Filtration of water. Secure a number of samples of 
neighborhood drinking water. Strain the different sam¬ 
ples through a funnel, putting a fresh filter paper or piece 
of absorbent cotton in the bottom of the funnel before 
each straining. 

In each case, is there any substance remaining on the 
filter paper or cotton? 

A good demonstration of the filtering power of soils 
can be made by taking several ordinary flower pots of 
quart capacity and filling them respectively with garden 
soil, fine sand, coarse sand, and gravels both fine and 
coarse, then pouring a pint of very muddy water into each 
filter and collecting in a drinking glass the water that 
leaks from each pot. 

A. Which kind of soil, garden soil, fine sand, coarse 
sand, fine gravel, or coarse gravel, lets through the least 
dirty water? 

B. What kind of soil lets through the dirtiest water? 

C. Is any of the water that you filtered entirely pure? 

D. How could you find out whether your filtered 
water has germs in it? 

E. If germs are present, how can the water be freed 
from them? 


HYGIENE BY EXPERIMENT 


168 


Exercise II. A Survey of Water Supplies 

Dr. B. C. Hendricks, of the University of Nebraska, has 
prepared the following studies of water-supply sources. 
You are expected to answer these questions that apply 
to the kind of water supply you have at home. 

i. A well survey. 

A . Depth and diameter of well ? 

B. Was the well dug, drilled, or driven? 

C. If dug, is it properly walled? 

D. What is usually the depth of water in the well? 

E. What seems to be the source of the water? 

F. Is the water hard or soft? 

G. Is the water clear, odorless, and tasteless? 

H. How long is it since the well was cleaned or ex¬ 
amined? 

I. How is water drawn from the well? 

J. Is the well so covered as to keep out all surface 
water and waste? 

K. Is the well perfectly rat-proof? 

L. Is there any danger of infection by water from 
house or outhouse drainage? 

2. A cistern survey. 

A. What is the capacity of your cistern? 

B. Is your cistern lined with concrete, or brick, or 
both? 

C. Does the cistern leak? 

D. For what purpose is the water used? 

E. Is the water clear, odorless, and tasteless? 

F. Is the cistern covered so as to keep out everything 
but rain water and air? 

G. What kind of filter is used, or is none used? 

H. Does the filter really do its work well? 

I. How is water drawn from the cistern? 


GOOD WATER FOR DRINKING 


169 


J. How frequently is the cistern thoroughly cleaned? 

K. What is the character of the roof from which the 
water for the cistern is collected? 

L. Are the eaves-troughs and conduits in good condi¬ 
tion? 

M. At what time of year is the cistern generally filled 
up? 

N. Is any care taken to have the roof fairly clean when 
water is allowed to go into the cistern? 

O. How is water from the roof taken care of when it is 
not entering the cistern? 

3. Central water supply for a community. If there is a 
pumping station and community reservoir, standpipe, 
or water tower, from which water is obtained for your 
home, make a study of the source and treatment of the 
water before it gets to your house. If the source is in 
wells, the study of wells provided above can be modified 
to fit the case. The report on the place of water storage 
is important in such a survey. Describe the source, 
storage, and care of the water that comes to your home if 
it is not taken from well or cistern. 

A . By what system is water supplied to your commu¬ 
nity? 

B. What reasons have you for thinking it is pure, or 
impure, as the case may be? 


STUDY TWENTY-EIGHT 

COMMUNITY CARE OF THE SICK 

You may have seen tacked up on some house in flam¬ 
ing color a card which read like this: “Quarantine. Scarlet 
fever. All persons are prohibited entering or leaving 
these premises under penalty of fine or imprisonment.” 
Perhaps you have wondered who put this card up, what 
right he had to do so, and whose business it may be, 
anyway, whether or not a family has scarlet fever. These 
and other questions very naturally come up and they 
require answer. 

Exercise I. Boards of Public Health 

1. Health boards in your state. Secure from the chief 
health officer of your locality copies of the rules and 
regulations of the state and local departments of health. 
Find out from these how the local and state boards of 
health are organized; and from any source get such 
further information as may be necessary to answer the 
questions that follow: 

A. What is the title of your chief state health officer, 
and what is his name? 

B. Who are the members of your state board of health ? 

C. What are some of the duties of the state board? 

D. What are the duties and powers of a county board? 

E. How is a village or city board of health organized? 

F. What are the duties and powers of such a board? 

G. Whose business is it to put a quarantine card on a 
house? 

H. Under what circumstances may a quarantine card 
be legally taken down? 

2. Dramatizing the activities of a health board. 

Proceed in your class or school to organize a mock board 


COMMUNITY CARE OF THE SICK 


171 



Fig. 48. A mock trial, “The State vs. Lawler.” It is probably the at¬ 
torney for the prosecution who is addressing the court. (At a trial, the. 
judge is referred to as “the court.”) A witness under examination is 
seated in the chair near the judge. The group at the right includes 
“Mrs. Lawler” and her attorney; also “Angelina” and the clerk of the 
court. The jury is seated near the wall. 


of health for a village, county, or city, depending on the 
kind of board that has control over the community in 
which you live. After this board has been organized, go 
through the procedure of ordering a quarantine on some 
house. If you have time, you can make your mock board 
of health act for your own school on cases of uncleanli¬ 
ness, disorder, school-yard behavior, and unhealthful 
conditions around schoolroom or grounds. Record in 
your notebook the answers to these questions: 

A. Who are the officers of your mock board of health? 

B. What powers have you given to your mock board? 

C. What cases have you had before your mock board? 

D. Why is a community better off for having a board 
of health? 












172 


HYGIENE BY EXPERIMENT 


Exercise II. Quarantining for Contagious Diseases 

i. Quarantine laws made interesting. It will add 
interest to your study of the health rules and quarantine 
regulations of your state or county if you will dramatize 
a case of violation of the rules of quarantine. The case 
that follows was successfully dramatized in one of the 
schools of Nebraska. With adaptations, it can be made 
to suit the regulations of any state. 

Mrs. Lawler’s daughter, Angelina, comes to school 
showing symptoms of scarlet fever. Her teacher, Miss 
Efficiency, has on her desk a copy of Ritchie’s Primer of 
Sanitation , and has learned to recognize these symptoms. 

According to the “Laws, Rules, and Regulations” of 
the Nebraska Health Commission, where no physician 
has been called to attend a pupil sick with a contagious 
disease, it is the legal duty of a teacher to report the case 
to her school principal or to the county superintendent of 
schools, who in turn must report the case to the local 
member of the county board of health. Consequently, 
on the morning Angelina Lawler appears with her inci¬ 
pient case of scarlet fever, the teacher sends her home, 
notifies the county superintendent, who in turn informs 
the county health officer, and he, following the state 
regulations, visits the home of Angelina and posts a red 
quarantine card on the house. 

Now, the Nebraska rules say that a scarlet-fever pa¬ 
tient must remain in quarantine for thirty days. Our 
Miss Angelina is sent home, let us say, on December io, 
and appears in school again on January 5. Mr. Good 
Citizen, knowing the danger to the school and to the 
community on account of Angelina’s premature return, 
causes Angelina to be arrested for violating the quaran¬ 
tine law. 


COMMUNITY CARE OF THE SICK 


173 


The case comes to court, and here is where our dramatiza¬ 
tion begins. 

The parties at the trial are the county judge; the county 
attorney; the attorney for the defense; Mrs. Lawler; 
Angelina; one or two of their neighbors as witnesses for 
the defense; the witnesses for the prosecution, who are 
Mr. Good Citizen and several others who have knowledge 
of the case, among them the member of the local board of 
health; and the jury, the members of which may be 
selected from among the parents and other visitors in¬ 
vited to come to the school on the day set for the trial. 
The maximum fine is $25 for violating the law. Is Mrs. 
Lawler guilty? 

Mrs. Lawler’s defense is that on January 5 she discov¬ 
ered that the quarantine card was down. She supposed 
that the officer had removed it, and so sent Angelina to 
school. Besides, she maintains, the girl was perfectly 
well. The prosecution says that Mrs. Lawler was seen 
taking the card down late on the evening of January 2, 
and that the girl had discharges from her ears when she 
returned to school. 

In working out the mock trial, you will need to ask 
questions of parents or others who have attended trials, 
to find out just how to conduct a case in court. You will 
also need to study the health laws of your state. You will 
find much to interest you in working out this trial. After 
you have held the trial, write in your notebook the an¬ 
swers to the questions that follow: 

A. What pupils joined in your mock trial for violation 
of the quarantine laws and what parts did they take? 

B. What was the specia 1 charge made against the de¬ 
fendant? 

C. What was the verdict of the jury; and what was the 
action of the judge? 


174 


HYGIENE BY EXPERIMENT 


2. Questions on quarantine. 

A. What does the word “quarantine” mean? 

B. In your state, what diseases are to be quarantined? 

C. Why are quarantine laws a good thing? 

D. What is the duty of anyone who discovers that a 
quarantine law has been violated? 

Exercise III. Hospitals and Sanitariums 

1. A visit to a hospital. If possible, make a visit to a 
hospital, or let someone who knows about hospitals 
report on them. Then write in your notebook the an¬ 
swers to these questions: 

A. Is your nearest hospital privately or publicly 
owned, or is it owned by an institution? 

B. Is it a free hospital or a pay hospital? 

C. How careful are the doctors and attendants to keep 
patients from being infected with germs 

D. Why are very sick persons usually better off in a 
hospital than in a home? 

E. Should there be a free hospital in every city or 
county for all very sick or badly injured persons? 

F. What is a pesthouse, and what is its importance? 

G. Where is your nearest hospital for the insane? 

H. Where is your nearest institution for the feeble¬ 
minded? 

2. Sanitariums. 

A. How is a sanitarium different from a hospital? 

B. Why is a sanitarium sometimes better for a con¬ 
valescent patient than his own home? 

C. Should every large community have a free sani¬ 
tarium? 

D. Where is the sanitarium nearest to your home? 

E. Distinguish between the term “sanitarium” and 
the term “sanatorium.” 


STUDY TWENTY-NINE 


INSPECTION OF FOODS AND SUPERVISION OF FOOD 

PRODUCTION 

More important than care of the sick and quarantine 
is prevention of infection in the first place. Among the 
most important means of prevention is the inspection of 
the local milk supply; and back of this is the inspection of 
dairy herds. Further guarding the health of the people 
is the United States Government with its inspection of 
meats, and with its pure-food laws. Then, too, there are 
state and local rules for keeping in a sanitary condition all 
markets where foods of any description are handled. 
But with all the laws and health officers we may have, 
the final guarding of the public health still depends on the 
people themselves. We must be on the alert to see that 
the laws are obeyed, and that we ourselves do what they 
require. The plan for food inspections in this Study will 
point the way for you to be of service not only to your 
community, but also to the well-meaning tradesmen who 
handle much of the people’s food. 

Exercise I. Studies of Milk 

1. Sediment in milk. Take a small pad of absorbent 
cotton and on it pour the last small portion of milk out of 
the container in which milk is supplied to your home. 

A. Do you find on the pad any specks, sediment, or 
colorations? 

B. If so, how do you think they got into the milk? 

C. Why does milk have so many germs in it? 

2. Milk diluted with water. To find out whether milk 
has been watered you will need a hydrometer. If you do 
not have one but have a dairy thermometer you may use 


'75 


17 6 


HYGIENE BY EXPERIMENT 



Fig. 49. The hydrometer test to determine whether or not milk has 

been adulterated with water. 


that. If the dairy thermometer does not float erect in 
water, wrap enough fine wire around the bottom of the 
thermometer to make it float vertically or nearly so. 
The higher degree marks should stand a little above the 
surface of the water. Put the milk to be tested into a 
tall, narrow vessel, such as a quart milk bottle or a long 
flower vase, and float the hydrometer or the thermometer 
in this milk. If the instrument floats higher than it did 
in the water, the milk is heavier than the water; but if 
lower, the milk is lighter than the water. 

A. Is milk heavier or lighter than water? 

B. When you add water to the sample of milk, does 
the instrument float higher or lower than before? 

3. A dangerous preservative. Formalin is sometimes 
used by unscrupulus dairymen to keep milk from 










INSPECTION OF FOODS 


177 


spoiling soon, for formalin, you will remember, is a germ 
killer. But it is poisonous to drink and should never be 
put into milk that is used for food. 

Put a few drops of formalin or formaldehyde into a 
sample of milk. Now, to show the presence of formalin 
in this sample, put into it a drop or two of a solution of 
ferrous chlorid. Very carefully pour a little strong 
sulfuric acid into the bottle at one side, holding the bottle 
well away from anybody’s face. The ring of color in the 
milk shows that the'milk has been treated with formalin. 

A . Describe the ring of color that is a test for formalin 
in milk. 

B. Why is Pasteurizing milk a better way to keep it 
from spoiling than putting formalin into it? 

Exercise II. Inspection of Food Sources 

i. Inspection of milk sources. The following questions 
are for use in a survey of a dairy, or of any place where 
milk is supplied for family use. Make a visit to some 
such source of milk supply and write in your notebook 
the answers to the questions that follow: y 

A . Is the barnyard clean and well drained? 

B. Is the cow barn well adapted to its purpose? 

C. Is the ground floor kept quite clean? 

D. Is the place kept reasonably free from cobwebs and 
other overhanging litter? 

E. Is the floor moisture-proof and rat-proof? 

F. Are there screens to keep flies out? 

G. Are the cow stables kept clean, and are there 
gutters to take care of the droppings? 

H. Are the cows kept quite clean? 

I. Have they passed the tuberculin test? 

/. Do the cows have wholesome water to drink? 


1 78 


HYGIENE BY EXPERIMENT 


K. Do the milkers wash and dry the cows’ udders 
before milking? 

L. Are their hands clean while milking? 

M. Do they wear clean, special milking suits? 

N. Are the men or women who handle the milk all in 
good health? 

O. Are the milking utensils kept perfectly clean? 

P. Is the milk pail provided with a cover? 

Q. Is the milking done through gauze over the milk 
pail? 

R. Is the gauze regularly boiled and dried before 
using? 

S. Is there a milk house separate from the barn and 
used for no other purpose than for keeping milk? 

T. Is the milk house thoroughly cleaned and well 
kept? 

U. Is the fresh milk cooled to at least 50° Fahrenheit 
as soon as possible after being taken from the cow? 
If so, why? 

2. Inspection of a bakery. Visit a bakery, and then in 
your notebook write the answers to the questions that 
follow: 

A . Is the building in a sanitary location? 

B. Are the premises generally kept clean? 

C. Is every precaution taken against rats? 

D. Is every precaution taken against cockroaches 
and other vermin? 

E. Is the building well screened in summer? 

F. Is the place well lighted? 

G. Are the rooms kept clean and free from flies? 

H. Do the clerks and bakers wear aprons? 

I. Are they thoroughly clean in dress and habits? 

J. Are the employees free from contagious diseases? 


INSPECTION OF FOODS 


179 


K. Are pet animals kept out of the bakery? 

L. Are utensils and machines kept quite clean? 

M. Is the garbage kept covered in metal cases? 

N. Are the bakery products kept under cover in 
show cases or elsewhere? 

O. Are they well wrapped when sent out? 

3. Inspection of a meat market. Visit a meat market 
and record in your notebook the answers to the questions 
that follow: 

A. Is the market in a sanitary location? 

B. Is the building well constructed? 

C. Is it rat-proof? 

D. Is the building well screened and free from flies? 

E. Are the surroundings kept clean? 

F. Are waste products kept in metal cans? 

G. Is all meat protected from flies and dust? 

II. Is the meat kept so that it cannot be freely handled 
by marketers? 

I. Are the counters, refrigerators, and other meat 
containers kept thoroughly clean? 

J. Are the clerks clean and healthy-looking? 

K. Are they protected with clean aprons? 

L. Are all utensils thoroughly cleaned daily? 

M. Is the meat supply Federally inspected? 

N. Is it city or village inspected? 

O. Are the carcasses kept carefully wrapped while 
being transported to the market? 

P. Is the meat delivered in covered wagons and 
kept wrapped until it reaches the purchaser? 

Q. Are the delivery wagons clean? 



STUDY THIRTY 

SURVEYS OF SCHOOLHOUSE AND HOME 

The old Greeks had a fable about their great god Zeus 
and the first man. Zeus gave the man one wallet in which 
to carry his own faults and another in which to carry the 
faults of others. The wallets were connected with a 
pair of straps, and the man decided to carry them 
suspended from his shoulders. He stuck his head between 
the straps, and this left one wallet resting on his back 
and the other just below his chest. But the wallet for 
his own faults was the one that swung at his back, 
while the one for his neighbors’ faults rested before his 
eyes; and to this day it is much easier for men to see 
the faults of others than to see their own. The moral 
of this fable here is that you should see to it that your 
own surroundings are as sanitary as you can make them 
before you inspect the surroundings of others. 

Exercise I. A Survey of Your School Building 

Keeping your own school building in mind, answer in 
your notebook the questions that follow. Allow two 
points as a maximum credit on each question. If the 
conditions in your school are quite different from those 
that a question seems to presuppose, give the question a 
liberal interpretation, and mark a credit appropriate to 
your school. For instance, in the questions about the 
well and the school sewage system, if you do not have a 
well or an outhouse at your school, give your school 
full credit if the conditions of sanitation are fully met 
in some other way. 

i. Is there a great deal of mud around the schoolhouse 
when it rains? 


180 


SURVEYS OF SCHOOLHOUSE AND HOME 


181 



Fig. 50. The Prescott School at Lincoln, Nebraska. The building is 
thoroughly modern; there is plenty of window space, and the grounds 
and walks are attractive. 


2. Is there a good walk leading from the road or street 
to the schoolhouse? 

3. Are the school grounds well drained; that is, free 
from all standing water in wet weather? 

4. Are there trees to relieve the excessive heat in 
summer and to serve as a windbreak in winter? 

5. Is there enough playground space that is suitable 
for healthful physical exercise? 

6. Is there a well of pure water on the grounds or 
conveniently accessible to the building, and is it so 
covered as absolutely to prevent the inflow of surface 
water and all filth? 

7. Are the outbuildings in good condition; that is, 
are they rainproof, do the doors swing freely, are the 
interior constructions adapted to their purposes, and 
are the buildings clean and free from unsightly marks? 

8. Does each closet have a suitable screen in front of 
it? 


















182 


HYGIENE BY EXPERIMENT 


9. Is there a suitable container for waste; as (1) a 
dry-earth closet, (2) a septic-tank container, or (3) a 
water-tight vault or box? 

10. Are the outbuildings thoroughly screened against 
insects and easily cleanable at frequent intervals? 

11. Are the floors of the outbuildings scrubbed at 
least once a week, and are the windows washed at least 
once a month? 

12. Are board floors of the school building oiled at 
least twice a year? 

13. Are the floors, doors, walls, windows, ceilings, and 
furniture of the school building kept free from accumu¬ 
lations of dirt and dust? 

14. Are the floors swept daily with an effective 
sweeping powder? 

15. Are the desks and other school furniture well 
dusted with a damp cloth? 

16. Is the schoolroom provided with a suitable and 
effective heating apparatus, either a well-jacketed stove 
or a well-installed furnace? 

17. Is the school building itself in such a condition 
that with a good heating apparatus, a proper tempera¬ 
ture can be maintained? 

18. Is there provision for the evaporation of a con¬ 
siderable quantity of moisture at the source of heat 
supply, in order properly to humidify the air? 

19. Is a good thermometer kept at the height of about 
four feet above the floor of the room and convenient to 
the teacher? 

20. Is a fairly uniform temperature of about 68° 
Fahrenheit maintained in the schoolroom all the time? 

21. Is the heating apparatus in charge of some one 
who is thoroughly capable of managing it efficiently and 
economically? 


SURVEYS OF SCHOOLHOUSE AND HOME 183 


22. Is the fuel abundant and in good condition, and is 
suitable kindling provided? 

23. Are there at least 200 cubic feet of space for each 
pupil in the room? 

24. For supplying fresh air to the heating apparatus, 
is there an inlet of as many square feet in cross section as 
there are rooms to heat; that is, if there are five rooms, 
does the opening into the fresh air pipe have an area of 
at least five square feet? 

25. Is there a foul-air exit at least 16 inches by 16 
inches in area in each room? This should be on the wall 
near the floor on the side of the room from which the 
heat supply comes. 

26. If the conditions specified in questions 24 and 25 
do not exist, is there a provision for open windows in 
mild weather and for window-board ventilation under 
all conditions? 

27. Whatever the system of ventilation, is it the 
practice to flush the room with fresh air at intermission 
times? 

28. Is the air of the room regularly renewed about once 
every 15 minutes? 

29. Is the total window-glass space equal to about one 
fourth or one fifth of the floor space? 

30. Are the sources of light on the long wall of each 
class room and on the left of the seated pupils, except the 
left-handed ones? 

31. Are the principal windows on either the east or 
the west side of the rooms, so that the sun can shine in 
directly during a part of the school day? 

32. Are the ceilings colored white or cream; the walls, 
light gray or light green; and the blackboards, black or 
dark green but not glossy? 

33. If there are windows to the rear or to the right of 


184 


HYGIENE BY EXPERIMENT 


the pupils, are their bases at least 7 feet from the floor? 

34. Are neutral-colored window shades provided for 
both the tops and bottoms of the windows, and are the 
shades regularly kept in correct adjustment? 

35. Are the school seats single, and are those of the 
same size in separate rows? 

36. Are the seats adjustable, and are they fitted to the 
child at first and refitted every four months thereafter? 

37. Are the devices for using ink kept in good order, 
and are the desks kept free from ink marks and other 
defacements? 

38. Are the decorations of the room simple and refined ? 

39. Are the seats, teacher’s desk, and other furniture of 
such a nature as to permit ready sweeping and cleaning 
underneath? 

40. Are the desks so related to the seats that a plumb 
bob dropped from the rear edge of a desk will fall two 
inches back from the front edge of the seat? 

41. Are there seats provided for the left-handed chil¬ 
dren, so set as to permit the light to come in over their 
right shoulders while they are writing? 

42. Are the children’s books kept in good order in 
their desks, and is there insistence on general freedom 
from litter in and about the desks? 

43. Is the drinking water wholesome and free from the 
possibility of germ infection? 

44. Is there easy access to drinking water any time of 
day without the necessity of disturbing the school in any 
way? 

45. Is there plenty of chance to get a drink when the 
demand is heavy, as at the close of intermissions? 

46. If individual drinking cups are used, are they kept 
where they are free from schoolroom dust? 


SURVEYS OF SCHOOLHOUSE AND HOME 185 

47. If individual cups are used, is the container for the 
drinking water so fixed that the water runs into the cups 
and cannot be dipped into? 

48. Are there facilities for the pupils’ washing their 
hands, (a) after the use of the toilet, (6) after handling 
soiled objects such as chalk and baseballs, and (c) just 
before eating luncheon? 

49. Are there individual towels kept in suitable re¬ 
ceptacles, or, better yet, paper towels conveniently at 
hand? 

50. Is there medical supervision in your school? 

51. What percentage does your school building score 
on this survey? 

Exercise II. A Sanitary Survey of Your Home 

The following survey questions are modified from Hoag 
and Terman’s Health Work in the Schools. Allow three 
points as the highest credit on each of the following 
items, and throw in one point for good measure at the 
last, as you record answers to the questions. 

1. Is the yard well drained, so that no surface water 
stands close to the house? 

2. Is the drainage natural or artificial? 

3. Is there no stagnant water near for breeding mos¬ 
quitoes? 

4. Are there no breeding places for flies near the house? 

5. Is the yard free from rubbish and litter? 

6. Is the yard kept attractive through the year? 

7. Are the outbuildings kept in good condition? 

8. Is the outside privy, if any, kept completely sani¬ 
tary? 

9. Is the cesspool, if any, cleaned out when necessary? 

10. Are wells and cisterns carefully protected? 


HYGIENE BY EXPERIMENT 


186 

11. Has the house good exposure to sun and air? 

12. Is the building kept in good repair? 

13. Does the air inside the house seem fresh and 
odorless? 

14. Is the house free from flies and mosquitoes? 

15. Is the house free from rats and mice? 

16. Is there an adequate and efficient heating system? 

17. Are the provisions for fresh and waste water ef¬ 
fective? 

18. Is the house lighting sufficient and well placed? 

19. Can floor coverings, if any, be easily removed and 
cleaned? 

20. Is the house free from useless hangings and decor¬ 
ations? 

21. Are the floors clean and smooth? 

22. Are the inside toilets, if any, thoroughly sanitary? 

23. Do the sleeping rooms have sunlight part of the 
day? 

24. Are the sleeping and living rooms easy to venti¬ 
late? 

25. Are the beds where air currents strike them? 

26. Are bed coverings frequently aired and cleaned? 

27. Does the kitchen have a cooler-closet or ice box? 

28. Is food kept where it is free from dust and insects? 

29. Are clean towels and other cleaning cloths pro¬ 
vided? 

30. Is there a light, dry room for storing vegetables? 

31. Are the basement rooms, if any, kept in clean, 
orderly condition? 

32. Is the attic kept in clean, orderly condition? 

33. Is the roof of the house free from leaks? 

34. What percentage of complete sanitation does your 
home score? 


PART THREE 

Personal Hygiene: Physiology 

TO THE BOYS AND GIRLS 

Imagine a little wayside pond with about twelve gal¬ 
lons of water in it and with something like four or five 
hundred trillions of microscopic, one-celled animals living 
in it, each one going hither and thither to get food for its 
own sustenance. 

Think of this same quantity of water and an equally 
large mass of cells, now organized so that the cells prac¬ 
tice a division of labor and hold fixed and interdependent 
positions. Instead of moving about through the liquid to 
absorb foodstuff, the cells have their food brought to 
them by flowing liquid. This liquid is made to circulate 
among the cells by the work of a special portion of the 
cells. 

Conceive this mass of cells and water as enclosed in a 
covering of skin and given the form of a human being, 
and you will have in mind a crude but essentially true 
picture of a human body. Man, physically, is then a sort 
of animated pond, a walking reservoir, but a very won¬ 
derful one withal. Indeed, the greatest of marvels is the 
human body, which has been given to each of us for a 
temporary dwelling place. 

While you are reading this page, three billions of red 
blood corpuscles are being manufactured in the red 
marrow of your bones, to say nothing of the multitudes of 
other activities within your wonderful cellular organiza¬ 
tion. The study of these cell activities is known as 
physiology. What hygiene is, you know from your study 
of Part One of these studies; and what sanitation is 
you know from your study of Part Two. 

187 


i88 


HYGIENE BY EXPERIMENT 


In Part Three, in addition to a further study of hygiene, 
you are to study something of Physiology , which is 
the science of the workings of the cells of the healthy body in 
maintaining life. 


STUDY THIRTY-ONE 

YOUR FOODS 

A skillful worker in metals can take quantities of 
copper, tin, and zinc and combine them into different 
metallic substances by varying the proportion of the 
metals in each mixture. One mixture, for instance, gives 
him the alloy of which a common cent is made, another 
yields bell metal, and still another provides the material 
for bronze statuary 

Now, just as the numerous metallic articles around us 
are made from a comparatively few primary metals, so 
the numerous things we eat are made up of a compara¬ 
tively few primary sorts of food. Thus it happens that 
we may have many different kinds of foods furnished for 
our meals, all made from a natural or artificial combina¬ 
tion of only five or six primary foodstuffs. A knowledge 
of the most common and important of these primary 
foodstuffs is very necessary to anyone who wishes to 
select his foods intelligently. 

Exercise I. What Your Foods Are Made Of 

Just as there are ways to find out whether a given piece 
of metal contains zinc, copper, or other elements, so there 
are ways to find out whether any particular food on your 
table contains any one of the primary food materials. 
You will find it interesting to make some of the tests for 
at least five different kinds of primary food materials. 

i. Proteins and how to identify them. The most 
important of all the primary food materials is called pro¬ 
tein. (Be careful to give three syllables to the pronuncia¬ 
tion of this word.) Its importance is due to the fact that 
it is the only kind of primary food material for which 

189 


190 


HYGIENE BY EXPERIMENT 



Fig. 51. A hot-lunch club is often successfully conducted in rural schools. 
The working officers are a cook, a housekeeper, and a bookkeeper; and 
the members serve in these places by turns. Besides getting hot lunch¬ 
eons at noon, the students have a chance to study foods and costs. 

there is no substitute. We could not live without one or 
more of the several varieties of proteins in our daily diet. 

Just as there is a way to tell whether there is copper in 
any given alloy, so there is a way to identify proteins in 
specimens of the class of materials from which we get our 
foods. To.make a test for proteins you will need a wire 
or a hatpin, and an alcohol lamp. An ordinary kerosene 
lamp will serve in place of the alcohol lamp, though it is 
not so convenient. Put a common feather on the point of 
the wire, and thrust the feather into the flame. Note 
the peculiar odor that comes from the burning feather. 
Any material can be known to have protein in it if, when 
burned, it yields an odor like that coming from the 
feather; and this is true even though other odors are 
mingled with this odor. Each pupil in the class should 












YOUR FOODS 


191 

make at least two tests for proteins in two samples of 
common table foods that have been brought to school. 
From the work of all the pupils, complete the record in 
the table outlined below: 


Food Tests for Proteins 


Foods Tested 

Effects of the 
Burning 

Conclusions 

Lean meat 

Butter 

Baked beans 

Cooked peas 

Peanuts 

Odor like burned 
feather 

No odor like burned 
feather 

Protein present 

No protein present 





Boiled egg (yolk) 

Boiled egg (white) 

Scum from boiled 
milk 

Gum from chewed 
wheat grains 












2. Carbohydrates and how to identify them. The name 
of the second most important kind of food is easily pro¬ 
nounced if you divide it up into syllables, thus: car-bo- 
hy'drates. There are two clases of carbohydrates that we 
need to know about and that we can test: namely, 
starches and sugars. 

A. Starches . Examine a sample of pulverized starch, 
and make a starch test as follows: To a small bit of 
powdered starch in a spoon add a drop or two of tincture 
of iodine. The starch will be turned a light or a dark blue, 

















192 


HYGIENE BY EXPERIMENT 


according as the proportion of starch in the sample is 
small or great. Test in the same way samples of the foods 
that are listed following this paragraph; and test as many 
other foods as you can, at least two tests being made by 
each pupil in the hygiene class. 

Food Tests for Starches 


Foods Tested for 
Starch 

Bread 

Peanuts 

Meat 

White potato 
Sweet potato 
Beans 
Banana 
Cane sugar 
Rice 

Macaroni 


Effects of Iodine 

Conclusions 

Dark blue 

Light blue 

No change 

Much starch 

Little starch 














- 



B. Sugars. There are two ordinary kinds of sugar, 
commonly known as cane sugar and grape sugar, but 
coming from many other sources besides sugar cane and 
grapes. If your teacher thinks it desirable, she can make 
the first test for grape sugar herself, in the presence of 
the class. The test is made by putting a raisin in a test 
tube or small vial, adding enough water to cover the rai- 


















YOUR FOODS 


193 


sin, and then putting in two or three drops of either Feh- 
ling’s or Haines’ solution, which can be bought at any 
drug store. On boiling the mixture of raisin water and 
the testing solution over the flame of an alcohol lamp, the 
liquid will turn reddish brown, for grape sugar is present. 
No other kind of sugar will yield this test. Apply the test 
to several other common foods, such as are suggested in 
the table below, and record results and conclusions. 

Food Tests for Grape Sugar 


Foods Tested 


Raisin 

White cane sugar 

Brown cane sugar 

White potato 

Sweet potato 

Bread 

Cake 

Candy 

Molasses 


Effects of the Test 
Solution 

Conclusions 

Reddish-brown color 

Color remains blue 

Reddish-brown color 

Grape sugar present 

No grape sugar 

Grape sugar present 














3. Fats and oils and how to identify them. The pri¬ 
mary foodstuff third in importance is fat, with its liquid 
variety, oil. The simple test for fats or oils consists in 
pressing the sample of food down on a piece of writing 

















194 


HYGIENE BY EXPERIMENT 


paper. If the paper is left somewhat transparent after 
drying, oil is present in the food tested. The pupils of the 
class should each bring to school two samples of common 
foods and make tests to complete the following table: 


Food Tests for Fats and Oils 


Foods Tested for 
Fats and Oils 

Effects of the Tests 

Conclusions 

Butter 

Yolk of egg 

Peanuts 

Walnuts 

Cheese 

Beef suet 

White of egg 

Paper quite transparent 

Paper partly transparent 

Much fat 

Some fat 












4. Ash and how to identify it. A fourth variety of 
primary foodstuff is known as “ash.” This ash includes 
common salt and many other mineral salts. The way to 
test for ash in any food is to burn a sample of the food 
completely. The material left is the ash that was in the 
food. For a careful test, the food must be burned in a 
very hot place in order to burn up all the other primary 
foodstuffs and leave the ash only unburned. To the table 
that follows add the names of five additional foods that 
will leave ash when burned. 















YOUR FOODS 


195 


Food Tests for Ash 


Foods Tested 

Effect of Burning 

Conclusions 

Oatmeal 

Ash remains 

Mineral salts present 




















5. Water as a primary foodstuff. We commonly think 
of water as a beverage, but it is a primary food as well, 
because it is used in building body tissue. It is so easily 
recognized that it does not need to be tested. Its presence 
in food, if in any quantity, is shown by the fact that the 
food will dry out on standing. What are the names of 
ten foods that you have reason to believe contain water 
in an appreciable amount? 

Exercise II. Questions for Investigation 

1. When carbohydrates are taken apart, what chem¬ 
ical elements are they found to be made of? 

2. What three elements are fats and oils made of? 

3. What three elements are present in starches and 

sugars? 

4. List ten foods that are rich in proteins. 

5. List ten foods that are rich in starches. 
















HYGIENE BY EXPERIMENT 


196 

6. List ten foods rich in fats or oils. 

7. Name ten foods yielding minerals. 

8. What are vitamins? 

9. Name five foods yielding vitamins. 

10. What primary foodstuffs are present in the follow¬ 
ing common foods: milk; white bread; lean meat; rice; 
white potato; sweet potato; peas and beans; corn bread; 
celery? 

11. Define vegetable foods, and name ten of them. 

12. Define animal foods, and name ten of them. 

13. Of what use is it to know the primary foodstuffs in 
the common foods? 

14. List some good habits with regard to the kinds of 
foods you eat. 


STUDY THIRTY-TWO 

HOW FOODS ARE DIGESTED 

You have been told that food for the cells making up 
the body is dissolved in water and is then carried by 
the circulating water to the cells that need the food. You 
have just been studying the kinds of foods the body uses, 
and you know that a good many of them will not dissolve 
in water unless something is done to make them soluble. 
Your next step in the study of the way in which the body 
is nourished is to learn how the foods may be made to 
dissolve in water. The process by which foods are ren¬ 
dered soluble in the liquid part of the blood is called 
digestion. A few experiments will help you to understand 
some of the forms of this interesting process. 

Exercise I. Processes of Digestion 

1. Starch and water. Put some raw or cooked starch 
into a glass of water. Does water dissolve starch; that 
is, does water take the starch up into itself so you can no 
longer see any of the starch? 

2. Sugar and water. Put a teaspoonful of sugar into 
a glass of water and stir once or twice. What happens to 
the sugar in the water? 

3. Effect of saliva on starch. In a test tube or vial two 
thirds full of water, boil a quantity of starch that will 
lie on a penknife point. Pour half of the starch paste that 
results from this boiling into another test tube or vial. 
Into one of your two samples of starch paste put as much 
as a teaspoonful of saliva which has previously been col¬ 
lected, and set the tube aside in a warm place for 10 
minutes. Keep the other sample of starch paste without 
change for the same time. Then put several drops of 

197 


198 


HYGIENE BY EXPERIMENT 



Fig. 52. A noonday luncheon served in the classroom. Foods served 
warm are more readily digested than foods served cold. In many schools 
a separate lunchroom is provided, and that is to be desired. 


Fehling’s or Haines’ solution in each portion of starch 
paste and proceed to bring each to the boiling point for a 
moment by holding the tube over the flame. 

A. What does saliva do to starch paste? 

B. How do you know that saliva does this? 

4. Why starch needs to be digested. Secure from a 
butcher two pieces, each about 3 inches long, of the small 
intestine of some animal. Wash these out thoroughly 
and tie a string around one end of each so as to make it 
into a pocket. Into one pocket, by means of a funnel, put 
some starch paste; and into the other put some molasses 
or strained honey. Now tie the upper ends of the two 
pockets, put them into separate glasses of water, and let 
them remain there for 24 hours. Then pour several drops 
of tincture of iodine into the water containing the intes¬ 
tine with starch in it. 






HOW FOODS ARE DIGESTED 


199 


A. Did the starch in your experiment get out into the 
water around the piece of intestine, and if not, why not? 

B. Pour some water from the other glass into a test 
tube or vial, add a few drops of Fehling’s or Haines’ 
solution, and bring to a boil. What do you find to be in 
the water? 

C. What do this study and the prior study show as to 
the ability of intestine wall to transmit food? 

D. Why does starch need to be changed to sugar in the 
food canal? 

5. Digestion of other foods. Most foods have to be 
digested before they can be useful to the body, as you 
have just seen. Starch is the only kind of food that saliva 
acts on. The other primary foodstuffs, and starch as well, 
are digested in other parts of the food canal. 

A. Do common salt and water have to be digested, 
and if not, why not? 

B. Why do lean meat, fat meat, and butter have to be 
digested? 

6. How the teeth help digestion. Turn to Part One, 
Study Six of this book and follow out the directions 
there given for the study of the teeth. 

7. The condition of your teeth. Have your teeth 
thoroughly examined and enter in your notebook the 
report on the condition of each one. 


A. Middle incisor 

B. Lateral incisor 

C. Canine 

D. First bicuspid 

E. Second bicuspid 

F. First molar 

G . Second molar 


UPPER TEETH 

LOWER TEETH 

Right | Left 

Right 

Left 





















































200 


HYGIENE BY EXPERIMENT 


Exercise II. Questions 
for Investigation 

1. What is digestion? 

2. What is an enzyme? 

3. Referring to Figure 
53, name the parts of the 
alimentary canal. 

4. Tell what happens 
to the different primary 
foodstuffs in a bite of 
buttered cold ham sand¬ 
wich as it passes down 
the following portions 
of the food canal: the 
mouth; the esophagus; 
the stomach; the small 
intestine; the large in¬ 
testine. 

5. Be able to trace on 
your body the outline of 
your stomach and liver, 
showing their locations. 

6. Similarly, be able 
to show the location of 
each of the salivary 
glands. 

7. What is a gland? 

8. What are the sali¬ 
vary glands? 

9. What is gastric 
juice? 

10. Where is the pan¬ 
creas? 



Fig. 53. A model of the alimentary 
canal. 





HOW FOODS ARE DIGESTED 


201 


11. What does it secrete? 

12. What is the vermiform appendix? 

13. What is appendicitis? 

14. Why should waste food not be left lying long in 
the large intestine? 

15. Of what four kinds of material is a tooth made? 

16. What are the three parts of a tooth? 

17. What are the temporary teeth? 

18. What are the permanent teeth? 

19. What is the most common cause of tooth decay? 

20. What are some abuses of teeth, in consequence of 
which they may decay? 

21. How do bad teeth injure health? 

22. How may you help to preserve your teeth? 

23. What are dental plaques? 

24. How should the gums be cared for? 

25. How can irregular teeth be straightened? 

26. How often should one visit a dentist? 

27. Write in your notebook a list of good-health prac¬ 
tices that aid digestion. 


STUDY THIRTY-THREE 

HOW FOODS SERVE THE BODY 

A gallon of high-grade gasoline will drive an auto¬ 
mobile 20 miles or more. A poorer grade will drive it 
hardly 15 miles. An autoist knows that the quantity of 
gasoline he must use on a given trip depends in part on the 
quality of the gasoline he puts into the tank. Similarly 
the power you get out of your food depends also in part 
on the kind of food you eat. You have come now to an 
important experiment that will show some of the dif¬ 
ferences in food quality. The experiment will have to be 
performed before the whole class in hygiene, but you can 
help your teacher in getting the apparatus together. 

Exercise I. The Fuel Value of Foods 

1. Making a calorimeter. For your studies of the 
relative heating powers of the primary foodstuffs you 
will need four homemade calorimeters or heat measurers, 
like the one shown in Figure 54. To make the four 
calorimeters you will need a dozen pie pans, 16 ten- 
penny nails, 4 pieces of fly screening measuring 4 by 6 
inches, and 4 boards about 10 inches square. 

Take a piece of board 10 or 12 inches square and on it 
set a good-sized pie pan. Around the pan, at equal inter¬ 
vals, drive 4 ten-penny nails about half an inch into the 
wood. Let them slant in over the edge of the pan so that 
they will support on their heads the outer rim of a second 
pan. Invert a third pan and place it over the second pan 
as a lid. 

Set in the first pan a piece of metal fly screening about 
7 inches long and 5 inches wide, with an inch of the 
screening bent down at each end. This will make a table- 


202 


HOW FOODS SERVE THE BODY 


203 



Fig. 54. The two calorimeters at the center are ready for lighting, 
while the other two are being prepared. The boy is weighing material 
to be tested. 


like support 5 inches square and with end legs an inch 
high. On this “table” is to be laid a piece of unglazed paper 
cut in a circle exactly the size of the pan, including the 
rim. 

In your notebook make a little drawing of your calori¬ 
meter. 

2. Testing the fuel value of foods. For your experi¬ 
ment you will need, besides the calorimeters, some kero¬ 
sene, a teaspoon, scales to weigh in fractions of an ounce, 
and samples of starch or sugar, dried beef, butter, a dairy 
thermometer, and a gallon of very cold water. 

When all is ready for the demonstration of the heat 
values of the three kinds of “fuel” foods, arrange the four 
calorimeters in a row on a table or desk before the class. 
Remove the two upper pans from one of the calorimeters, 
















204 


HYGIENE BY EXPERIMENT 


and on the center of its circular paper carefully pour an 
even teaspoonful of kerosene. Replace the second pan 
on the nail heads and very carefully pour into it an exact 
pint of the ice-cold water. Take the exact temperature 
of the water in the pan and then cover it with the third 
pan inverted. 

Treat the second calorimeter in the same way, but 
put one sixth of an ounce (5 grams, or the weight of a five- 
cent piece) of starch or sugar on the paper before adding 
kerosene. Be careful to see that the food and the kerosene 
are thoroughly mixed on the paper without the loss of any 
materials. Treat the third calorimeter as the second, but 
use one-sixth of an ounce of dried beef (dried in an oven 
to a crisp, but not charred) in place of the starch. Into 
the fourth calorimeter, put one sixth of an ounce of pure 
butter instead of the starch or beef. 

When everything is ready, set fire to all four papers. 
If necessary, do some “ poking” with a small metal 
“poker” to keep the fires going. As soon as each fire goes 
out completely, once more take the temperature of the 
water in each pan. Record the results in your notebook, 
as indicated in the form of table that follows: • 


Table of Fuel Values 


Temperature 

First 

Reading 

Second 

Reading 

Differ¬ 

ence 

Difference 
Minus the 
Effect of 
Kerosene 

Pan 1 (kerosene only) 
Pan 2 (carbohydrate) 
Pan 3 (protein) 

Pan 4 (fat) 







































HOW FOODS SERVE THE BODY 


205 


To get the figures for the fourth column above, sub¬ 
tract the difference in temperature shown in the third 
column for the kerosene alone (Pan 1) from each of the 
remaining differences in Column 3. The fourth column 
now shows the heating power of a sixth of an ounce of 
carbohydrate (starch), of protein (dried beef) and of fat 
(butter). If the work has been carefully done the beef 
and the starch will show about the same results in Col¬ 
umn 4, while the butter will show about twice as great a 
result. The values in Column 4 are called heat units. 
If you have used a Fahrenheit thermometer and a full 
pint of water (which weighs about a pound) you have for 
each degree of heat an English heat unit of energy. A heat 
unit may be defined as an amount of heat that will raise 
a unit weight of water through one degree of temperature. 
The English unit employs a pound of water and a degree 
of heat measured by a Fahrenheit thermometer. The 
French unit (called a calorie) employs a kilogram of 
water and a degree of heat measured on a Centigrade 
thermometer. 

It must be recognized that in your experiment with the 
calorimeters there was lost into the surrounding air about 
half the heat from the burning substances. You must, 
therefore, double the results in Column 4 of your table 
to get a result near to what a sixth of an ounce of the 
food in each case would yield in heat units. Now multi¬ 
ply the doubled results by 6 so as to indicate roughly 
what a whole ounce of each kind of foodstuff will yield 
in heating power. 

A. What is the heat-unit value of an ounce of starch 
(carbohydrate)? 

B. What is the heat-unit value of an ounce of beef 
(protein) ? 


206 


HYGIENE BY EXPERIMENT 


C. What is the heat-unit value of an ounce of butter? 

3. A well-balanced ration. Careful scientists say that 
a well-balanced ration per meal for an average adult 
consists of about 5 ounces of dry carbohydrates, 1 ounce 
of dry protein, and 1 ounce of fat. Remember these 
figures and these proportions. An average day’s needs 
for all three meals will thus come to 21 ounces of dry 
foodstuff. How many heat units would there be in a 
well-balanced ration for a day, as you calculate them 
from the values you got in your calorimeter experiments? 

4. Review. Refer to experiments in connection with 
food studies, which were made in Studies Seven and Eight 
of Part One. What have you learned from that review? 

Exercise II. Foods for Building and Repairing Tissues 

1. Proteins as tissue builders. Fill two test tubes or 
small bottles half full of clear rain water. To one of these 
add sugar equal to one twentieth by weight of the water. 
Fill a third similar bottle two thirds full of Pasteurized 
skimmed milk or separated milk. Ordinary milk contains 
about 5 per cent of sugar and 2 per cent of protein. To 
each of your bottles now add a drop of fresh liquid yeast. 
Set the three bottles aside in a warm place for a day, 
then place a drop of liquid from each bottle on three 
separate microscopic slides. Examine each drop through 
a compound microscope that will magnify about a hun¬ 
dred diameters, and note which drop has the most yeast 
plants growing in it. Which drop has the most and which 
the fewest plants? What does this show? 

2. Salts as tissue builders. Find out, from any source, 
the nature and cause of the disease known as “rickets.” 

A. What is one function of the salts or “ash” in foods? 

B. What is another function of salts in the blood? 


HOW FOODS SERVE THE BODY 


207 


Exercise III. Questions for Investigation 

1. What is a food? 

2. What two purposes do carbohydrates serve in the 
body? 

3 What two purposes do fats and oils serve in the 
body? 

4. What three purposes do proteins serve in the body? 

5. Why is milk so good a food for animals that are 
growing? 

6. Why are eggs so excellent a food? 

7. What causes scurvy? 

8. What is pellagra, and what causes it? 

9. If you eat more carbohydrates and fats than you 
need, what does your body do with them? 

10. If you eat more proteins than you need, what 
becomes of them? 

11. Why is it not good for one to eat more meat and 
other proteins than the food canal can absorb, even in 
their digested form? 

12. Why should so much gas form in the bowels 
when one eats excess proteins? 

13. What is meant by the term “vegetarian”? 

14. Who usually has the greater endurance, a vege¬ 
tarian or a meat eater? 

15. Give four reasons why it is wise to eat meats only 
moderately. 

16. Why are fruits and vegetables very healthful for 
most people? 

17. Why is constipation a great enemy of good health ? 

18. Why should you chew your food thoroughly 
before swallowing it? 

19. What are some good habits of eating for^you to 
form? 


STUDY THIRTY-FOUR 

STIMULANTS, NARCOTICS, AND DRUGS 

About one-fifth of the air you ordinarily breathe is 
oxygen. If the air were wholly oxygen, do you think your 
lungs would be as large as they are, since the only part of 
the air that the lungs use is the oxygen? If the pull of 
gravity were twice what it is, would your bones be 
stronger and your muscles more powerful? Man has 
grown in a wonderful way to fit into the world in which 
he lives; and just as a fish cannot live out of water, so 
man cannot endure any very great departure from his 
natural way of living. It is because their use is not 
natural to man that stimulants, narcotics, and drugs are 
so demoralizing in their effects. Even the common forms 
of drugs do some harm, because they are unnatural. 
Under some conditions, however, there are drugs that 
temporarily do more good than harm; but they should 
be taken only on the advice of a skilled physician. It 
will be worth while to study some of the common forms 
of drugs at first hand. 

Exercise I. Common Stimulants 

1. Tea and coffee. Recall or repeat the work on tea 
and coffee in Study Seven, Part One. 

A. What is a stimulant? 

B. What is the stimulant in tea and coffee? 

C. What is the astringent in tea and coffee? 

D. What is the way to make tea and coffee so they 
will be least harmful? 

E. Why are tea and coffee not wholesome for boys and 
girls? 

2. Cocoa. Examine a sample of powdered cocoa used 
in making beverages. Test it for oil or fat, by pressing a 

208 


STIMULANTS , NARCOTICS, AND DRUGS 


209 



Fig. 55. The little machine, called a sphygmograph, is 
fixed to the wrist for making a pulse record. The record 
is traced on the smoked paper around the revolving 
drum, called the kymograph. The effect of tobacco 
shows itself in the user’s pulse. 


bit of it down on glazed paper to see if the paper becomes 
transparent. Test another small quantity of it for grape 
sugar by the use of Fehling’s or Haines’ solution. In 
addition to the food materials, there is in cocoa a stimu¬ 
lating substance somewhat like that in tea and coffee. 
This is called theobromine. Cocoa contains no astringent 
substance as do tea and coffee. 

A. What is the appearance of cocoa used for bever¬ 
ages? 

B. What primary food materials, if any,does it contain? 

C. Why is cocoa more wholesome than tea or coffee? 
























210 


HYGIENE BY EXPERIMENT 


Exercise II. Common Narcotics 

i. Alcohol. This substance was long regarded as a 
stimulant when taken in small quantities, and as a nar¬ 
cotic or deadening substance when taken in larger 
quantities. The view now held is that alcohol is always 
a narcotic, for while it sometimes seems to stimulate, it 
does not really do so but is a deadener from the very first. 

It happens that there are two sets of nerves that control 
the heart. One set makes the heart beat slower and the 
other set makes the heart beat faster. Alcohol in the 
blood acts on the former set of nerves first and deadens 
them, so that the second set of nerves acts unopposed. 
This makes the heart beat vigorously and sends blood 
rapidly to skin, muscles, and brain; and the person then 
seems to be excited. If a man driving a spirited horse 
loses the lines, the horse goes faster, not because he has 
been excited, but because the restraint has been taken 
off and he is left free to go as fast as he will. So, with 
the heart. The man who fills up on alcohol is like a driver 
who throws his lines away. But alcohol continues to work 
on a man’s nerves and presently begins to deaden the 
second or excitor set of nerves also. After that it is easy to 
see that alcohol is a narcotic, for the man’s heart begins 
to slow down and all his movements become slack. 

Recall or repeat the experiment with alcohol in Study 
Seven, Part One. 

A. What is the difference in effects between a stimu¬ 
lant and a narcotic? 

B. What is the appearance of alcohol? 

C. What are two important industrial uses of alcohol? 

D. What is the effect of alcohol on cell substance? 

E. In what two ways can you test for the presence of 
alcohol in a liquid? 


STIMULANTS , NARCOTICS, AND DRUGS 


211 


F. Why do you suppose people have ever drunk alco¬ 
holic beverages? 

G. By examining the labels on patent medicine bot¬ 
tles, find out the percentage of grain (ethyl) alcohol in 
each of the proprietary “remedies” listed: Peruna, Lydia 
E. Pinkham’s Vegetable Compound, Hostetter’s Bitters, 
Hood’s Sarsaparilla, Warner’s Safe Cure, Tanlac, Jaynes’ 
Expectorant, Wakefield’s Blackberry Balsam, Mrs. Wins¬ 
low’s Soothing Syrup, and Castoria. 

2. Tobacco. There is reason to believe that tobacco 
acts in much the same way that alcohol does, tending to 
excite heart action immediately after it is chewed or 
smoked, but a little later producing a slowing-down effect. 
Look at the picture, Figure 55, to see how a pulse-tracing 
machine is used to tell the effect of the use of tobacco on 
heart action. Then study the records of pulse waves 
shown below and answer the questions that follow: 




Fig. 56. These lines represent three different tracings made on the 
kymograph. The top tracing was made after a period during which 
the subject used no tobacco, dhe middle one was made just after a 
smoke had been started. The lower one was made at the end of a long 
smoke. 


212 


HYGIENE BY EXPERIMENT 


A . How does the heart of a tobacco user seem to work 
just before he uses tobacco? 

B. How does the heart of a tobacco user seem to work 
just after he uses some tobacco? 

C. How does the heart of a tobacco user seem to act 
after he has been smoking or chewing a while? 

3. Review. Recall or repeat the experiments with 
tobacco in Study Eight, Part One. 

A. What is the particular narcotic substance that is 
found in tobacco? 

B. What are three liquids in which this narcotic is 
soluble? 

C. What is the effect of nicotine on insects and small 
animals? 

4. Curing the tobacco habit. If a boy has been so 
unfortunate as to have acquired the tobacco-using habit 
in any form, he can use the recipe that follows, to help 
him break off easily. 

Use a 10 per cent solution of silver nitrate, which can 
be prepared by any competent druggist. Apply this 
solution with a camel’s hair brush to the tip and edge of 
the tongue every two or three days for two or three weeks 
Make these applications often enough to cause the loss of 
a desire to use tobacco. The combination, in the saliva, of 
silver with the products of tobacco results in a brassy taste. 

Exercise III. Patent Medicines and Their Drugs 

The following list of kinds of patent medicines may 
serve as the basis for classifying a collection of medicine 
bottles. Collect the bottles with labels still on, but have 
the bottles clean. 

1. The “ethical preparations,” to some extent bene¬ 
ficial. 


STIMULANTS , NARCOTICS, AND DRUGS 213 

2. Fraudulent but not injurious or dangerous “reme¬ 
dies” 

A. The cures, if any, are mentally induced. 

B. The use of the remedies usually serves only to delay 
proper treatment. 

3. “Remedies” to some extent dangerous, but not in¬ 
ducing a drug habit. 

A. Hair “restorers” containing sugar of lead. 

B. Cosmetics containing corrosive sublimate. 

C. Blood “purifiers” containing iodid of potassium. 

D. Consumption “cures” containing chloroform. 

4. Dangerous to life and usually inducing a drug habit. 

A. “Remedies” whose chief element is alcohol. 

B. “Remedies” containing opium and its derivatives. 

a. Forms: Pure opium, laudanum, paregoric, 
morphine. 

b. Examples: Soothing syrups and consumption 
“cures.” 

C. “Remedies” containing cocaine; for example, ca¬ 
tarrh cures. 

D. “Remedies” containing acetanilid, which is a pow¬ 
erful heart depressant. Acetanilid is used in practi¬ 
cally all headache medicines. 

Exercise IV. Questions for Investigation 

1. What are theine and caffeine? 

2. What is tannin? 

3. Why are tea and coffee not good for you to drink? 

4. If you have formed the habit of drinking tea or 
coffee, which have you been drinking, and how many 
cups do you take in a day? 

5. Why is cocoa a more healthful beverage than tea or 
coffee? 


214 


HYGIENE BY EXPERIMENT 


6. Why is milk the most nourishing of all beverages? 

7. What is the difference between grain alcohol and 
wood alcohol? 

8. What is denatured alcohol? 

9. What is the effect of alcohol on the general health? 

10. What is the effect of alcohol on length of life? 

11. What is the effect of alcohol on the structure of 
cells? 

12. What is the effect of alcohol on the mind? 

13. What is the effect of alcohol on muscle control? 

14. Name some diseases caused by alcohol. 

15. Why is, or is not, alcohol a food? 

16. Who were the first people known to use tobacco? 

17. Who is said to have started the practice of smoking 
among English-speaking peoples? 

18. Why is the use of tobacco so widespread? 

19. What is nicotine? 

20. How does the use of tobacco affect body growth? 

21. How does the use of tobacco affect the muscles? 

22. How does the use of tobacco affect the nervous 
system? 

23. How does the use of tobacco affect the mind? 

24. Why should boys and girls not use tobacco? 

25. Mention five other drugs besides nicotine that act 
as narcotics. 

26. How much do Americans spend annually for to¬ 
bacco? For cigars? For cigarettes? For public schools? 

27. In order to keep up the business and make money 
for the tobacco companies, how many boys and girls 
every day, do you suppose, must learn to smoke a part of 
the sixty billions of cigarettes used in America annually? 

28. What are some good habits to form with respect to 
stimulants, narcotics, and drugs? 


STUDY THIRTY-FIVE 

THE AIR AND BREATHING 

You have had the experience of working somewhere in 
the midst of various noises, to most of which you paid no 
attention until one of them stopped sounding. In general, 
the things that are with us constantly we pay little or no 
attention to. So it is not strange that men gave little or 
no thought to the composition of the air up to a century 
and a half ago. Then, one of the interesting items of 
news that Benjamin Franklin must have read in the 
English newspapers was that Joseph Priestley had dis¬ 
covered oxygen. While you cannot conveniently repeat 
the experiments that Priestley performed when he first 
learned about oxygen and its presence in air, there is a 
simple experiment that you can easily perform, which will 
do as well for your purpose. 

Exercise I. Studies of the Air and Its Constituents 

• 

i. Finding the oxygen in air. Fill a wash pan or other 
shallow vessel half full of water and on it float a flat cork 
that is about 2 inches across and inch thick. Insert the 
wood end of a match in a small hole in the center of the 
cork so that the head of the match will ride about an 
inch above top of the cork. 

Invert a good-sized water glass (the less sloping the 
sides the better), and hold it in one hand near the match 
head. With a lighted match, set fire to the floating 
match and instantly cover the floating cork and match 
with the glass. Let the rim of the inclosing glass rest close 
to the bottom of the pan. The white fumes from the 
burning match head are caused by the fact that the 
phosphorus in the match head eagerly takes up the 

215 


216 


HYGIENE BY EXPERIMENT 



Fig. 57. The lung test. This spirometer is sold as a 
regular piece of laboratory equipment. The boy is using 
a sterilized glass mouthpiece, as he should do; but he 
might make a better record if he kept his chest clear 
of the table. (See also Figure 10.) 

oxygen in the enclosed air and makes a white compound 
called phosphorus pentoxid. These white fumes quickly 
dissolve in the water, and thus the oxygen that was in 
the air is taken down into the water and the water from 
below comes up to take the place of the oxygen — the 
water level rises within your glass. 

After the flame dies out, raise the glass until its rim is 
just under the surface of the water in the pan, cover the 















THE AIR AND BREATHING 


217 


mouth of the glass with a piece of cardboard or a piece of 
window glass by passing it under the water and pressing 
it snugly up against the rim of the inverted glass. Now 
turn the glass right side up, still keeping the lid closely 
on so as to retain the water that had flowed up into 
the cup. Estimate the fraction of oxygen found in ordi¬ 
nary air, basing your estimate on the quantity of water 
that took the place of the oxygen. Make some allowance 
for the fact that bubbles of the heated air escaped during 
the burning. What proportion of ordinary air consists 
of oxygen? 

2. Nitrogen in air. Ordinary air is a mixture of several 
gases, that remaining in the cup after the burning being 
mainly a gas called nitrogen. Slip the cover off the glass 
of nitrogen and water, insert a burning match into the 
nitrogen, and see what happens. Replace the cover 
quickly. Why did the match go out? 

3. The effect of nitrogen on an insect. Put a grass¬ 
hopper or other insect under the cover and let it rest on 
the floating cork, putting the cover down tightly. At the 
same time put a similar insect in a similar glass with just 
as much water in it as there is in the first glass; but let 
the air in the second glass be fresh. Cover the second 
glass tightly. Watch both glasses for a few minutes. 

A. Why does the insect in nitrogen gas keel over, 
while the one in ordinary air does not? 

B. Take out the keeled-over insect and give it some 
fresh air. What happens when a partly smothered insect 
is given fresh air, and why is this so? 

4. The oxygen in exhaled air. Repeat the first experi¬ 
ment in this study; but before covering the flame of the 
floating match, see that the glass is filled with air exhaled 
from your lungs. This air can be kept in the glass by 


218 


HYGIENE BY EXPERIMENT 


holding a cardboard over it until you are ready at once to 
cover the flame. Compare the water that came in this 
time with the quantity that was in the glass at the end 
of the first experiment. Keep the glass covered for later 
use. What evidence have you that exhaled air has less 
oxygen in it than inhaled air has? 

5. Testing for carbon dioxid. Slake some fresh lime in 
a big bottle of clear rain water and let stand until there 
is clear limewater on top. Pour this clear limewater into 
a bottle by itself, letting none of the lime at the bottom 
carry over. Take two clean bottles, such as pint milk 
bottles, and put a teaspoonful of clear limewater into 
each of them. Now fill up one bottle with ordinary air 
and the other with exhaled air. Shake the bottles, and 
note the color of the water in each. A gas called carbon 
dioxid is the only ordinary gas that will turn limewater 
milky. What two things have you learned from mixing 
limewater with fresh air and with exhaled air? 

6. Testing the breath for carbon dioxid. Take a small 
vial or test tube and put a little limewater in it. Now in¬ 
sert a glass tube and blow through it so as to make bubbles 
in the limewater. 

A. What happens to the limewater when you blow 
your breath through, and why does this happen? 

B. The addition of a large amount of carbon dioxid 
will dissolve the white particles that a small amount of 
carbon dioxid may have caused to form in limewater. 
Keep on blowing through the tube for a while. What 
is the result and what causes it? 

7. Amount of carbon dioxid in exhaled breath. In 
the center of each of two saucers of water put a small piece 
of stick potassium hydroxid. The piece should be about 
as big as the last joint of your little finger. Over one sau- 


THE AIR AND BREATHING 


219 


cer invert a pint milk bottle with ordinary air in it, and 
over the other invert a similar pint milk bottle with 
exhaled air in it. Potassium hydroxid absorbs or takes 



Fig. 58. Apparatus for generating carbon dioxid and for testing it. 


up the carbon dioxid gas, and water comes into the 
bottle to take its place. What fraction of exhaled air is 
carbon dioxid, as you judge from your experiment with 
potassium hydroxid? 

8. Experiments with carbon dioxid. Provide a carbon- 
dioxid generator such as is shown at the left of Figure 58, 
and perform the experiments called for. 

A. Fill a test tube or bottle with carbon dioxid and 
put a stopper in it. What does carbon dioxid look like? 

B. Take another test tube or bottle filled with ordi¬ 
nary air and into it slowly “pour” the contents of the bot¬ 
tle of carbon dioxid. Now add some limewater and 
shake. How do you know that carbon dioxid is heavier 
than air? 

C. Fill one of two equal-sized bottles with carbon 
dioxid, and leave ordinary air in the other. Catch two 



































220 


HYGIENE BY EXPERIMENT 


insects of the same kind, put one in each of these bottles, 
and then let the bottles stand for some minutes. To 
find out whether the insect in the carbon-dioxid bottle 
has been poisoned, or whether it is merely motionless 
from want of oxygen, take it out and keep it in fresh air 
for a while. Why does an insect keel over when confined 
in a bottle of carbon dioxid? 

D. Would you judge from these experiments with 
insects that carbon dioxid is poisonous — that it is de¬ 
structive of animal tissue? 

E. If a man drowns, does he die because the water 
poisons him? 

F. If a miner is overcome with choke damp, what 
causes him to lose consciousness? 

9. The sources of carbon dioxid in nature. Prepare a 
carbon-dioxid tester from a quart Mason jar, as shown at 
the right in Figure 58. Have at hand also four additional 
Mason jars, each with its own lid. To test for the pres¬ 
ence of carbon dioxid in ordinary air, pour a pint or more 
of water into your tester through its funnel, first making 
sure that the lid of your tester is screwed down tightly on 
a good rubber band. The water passing into the jar will 
force the air out through the delivery jet of clear lime- 
water. If the limewater takes on the appearance of milky 
water, you may be sure that there is an appreciable 
amount of carbon dioxid enclosed in the air in the jar. 

A. Does ordinary air have an appreciable amount of 
carbon dioxid in it? 

B. Into a Mason jar, pour water to the depth of an 
inch, and then put a short leafy twig in the water, letting 
it stand on the broken end. Put the lid on loosely, and let 
the jar stand in a warm, dark place for a day and night. 
Test for carbon dioxid, as suggested above, by trans- 


THE AIR AND BREATHING 


221 


ferring the tester lid to the can with the leafy twig and 
screwing it down tightly. What evidence do you have 



Fig. 59. The gas content of the air as 
our lungs receive it and as they throw it 
out. The percentage of nitrogen and 
other gases that our lungs do not act 
upon remains the same. 


that leaves from a broken twig do or do not give off car¬ 
bon dioxid? 

C. Put pieces of decayed fruit in a second jar, place 
the lid on loosely, and let stand in a warm place. In 
24 hours exchange can lids as before and test for carbon 
dioxid. Does decayed fruit give off carbon dioxid? 

D. Put a handful of viable seeds (seeds that will grow), 
such as peas, beans, or corn, into a third jar, cover with 




























222 


HYGIENE BY EXPERIMENT 


water, and put the lid on loosely. Keep the jar for a day 
and night in a warm, dark place; then test for carbon 
dioxid as before. Do germinating seeds give off carbon 
dioxid ? 

E. Into a fourth jar, put water an inch deep, then add 
a tablespoonful of molasses or brown sugar and half a 
cake of yeast well broken up. Cover loosely with a lid, 
and keep in a dark, warm place for 24 hours. Test for 
carbon dioxid. Does growing yeast give off carbon dioxid ? 
Why is yeast put into dough? Why does dough have to 
be kneaded? 

F. Name a half-dozen sources for the natural produc¬ 
tion of carbon dioxid. 

10. Why we breathe. Study the diagram, Figure 59, 
and then answer the questions that follow. 

A. What does the air gain and what does it lose when 
passing through the lungs? 

B. What, therefore, seem to be the two important 
purposes of breathing? 

Exercise IT. Studies of Breathing 

1. Your three lung capacities. You need now to 
measure your lung capacities. To do this it will be neces¬ 
sary to provide a lung tester or spirometer, such as is 
described on page 15 and illustrated in Figure 10. Note, 
as shown in Figure 60, that after taking in an ordinary 
breath {tidal air) you can still take in more air {com- 
plemental air). You should note further that after giving 
off an ordinary breath (tidal air) you can give off still 
more air {supplemental air). These three capacities make 
up what is known as your vital capacity. Even after 
expelling all the air you can, there are still about 100 
cubic inches of air left in your lungs {residual air). 


THE AIR AND BREATHING 


223 


A. Fill the lungs as full as possible and then exhale 
into a lung tester or spirometer all you can. What do you 
find to be the volume of your vital capacity? 

B. Just after taking in an ordinary breath, exhale into 
the spirometer all you can. What do you find to be the 



1 ir 

I i rn iSST 

l |i2dl 

(D 

COMPLEMENTAL AIR- / 

| Iccuife 

■ J -~.o. 

J £xSK : 

AT GREATEST INSPIRATION k 

® ( 

H 1 13 nil 

TIDAL AIR- 


ATCIOINAR.Y INSPIRATION ffT 

SUPPLEMENTAL AIR- ft / i 

1 iS 

1 Ij.iooS 

AT ORDINARY EXPIRATION fk 

® llm 

RESIDUAL AIR- 


AT GREATEST EXPIRATION 


Fig. 60. Lung capacities at different stages of breathing. The figures 
apply to the normal adult, whose total lung capacity, as represented 
by the content of bottle, is about 350 cubic inches. For the average 
fifth grader, the figures given should be cut in two. 


volume of your combined tidal and supplemental capacity? 

C. Subtracting the above result from your vital 
capacity, what do you find to be your complemental 
capacity? 

D. Just after giving off an ordinary breath, exhale into 
the spirometer as much air as you possibly can. What do 
you find to be the volume of your supplemental capacity? 

E. Subtract the result for your supplemental capacity 
from the measurement taken in B. What do you find to 
be the volume of your tidal capacity? 

2. Finding your chest’expansion.j Placing the tape line 
at the level of the lower end of your breastbone, take the 























224 


HYGIENE BY EXPERIMENT 


circumference of your chest when all the air possible has 
been expelled from the lungs. Take the measurement 
again when the lungs have been fully inflated. Find the 
difference between the two measurements. What is your 
chest expansion? 

3. How air gets into and out of the lungs. Take a 
stopperless pint or quart bottle with the bottom broken 
out. Hold this bottle so that its base will be just under 
the surface of the water in a deep vessel. Place a burning 
match or candle at the bottle’s mouth as you thrust the 
bottle farther down into the water and as you quietly 
bring it up again. What may it be that makes the air 
come into and go out of your lungs, judging from your 
experiment with the bottomless bottle? 

4. Abdominal breathing. Draw your breath several 
times by using the muscles of only the lower half of the 
trunk (<diaphragm and abdominal muscles, but not the rib 
muscles). See the fourth experiment in Study Four, Part 
One. 

A. What is abdominal breathing? 

B. Do men or do women use this kind of breathing 
the more? 

5. Chest breathing. Breathe by using the muscles of 
only the upper half of the trunk (the rib muscles), in¬ 
haling and exhaling several times. 

A. What is chest breathing? 

B. Do men or do women use this the more? 

6. Mixed breathing. Breathe now by using both 
methods. 

A. What is mixed breathing? 

B. What kind of breathing is best for people gener¬ 
ally? 

7. Volume of air you breathe per hour. By careful 


THE AIR AND BREATHING 


22 5 


observation, discover the number of times you ordinarily 
breathe in a minute. Multiply the number of cubic inches 
you ordinarily breathe (your tidal capacity) by the 
number of your breaths a minute, and then multiply this 
result by 60. How much air do you breathe in an hour? 

Exercise III. General Questions 

1. What is air composed of? 

2. Why do you need air? 

3. What would be the probable change in the size of 
people’s lungs if the proportion of oxygen and nitrogen 
in the air were to be interchanged? 

4. Why is carbon dioxid sometimes called “choke 
damp” ? 

5. What are some uses of carbon dioxid? 

6. What are two purposes of breathing? 

7. How do you get air into and out of your lungs? 

8. What type of breathing do you mostly employ? 

9. What are some things you could do to increase your 
lung capacity? 

10. If your lung expansion is not at the standard for 
one of your height and weight, how much is it off, and in 
which direction? 

11. Set down in your notebook some of the means by 
which you can be sure to get good air indoors. 


STUDY THIRTY-SIX 

RESPIRATION AND THE ORGANS OF RESPIRATION 

Why is it that you can hold your breath scarcely a 
minute, while the Red Sea pearl divers, without appara¬ 
tus, can stay under water more than a minute — 
sometimes even more than 2 minutes? The reason is that 
these divers have had long practice in developing lung 
capacity. They take more air under the water with them 
than untrained men could, and that is the secret of their 
staying under longer. But why does one need air at all? 
What element of the air is directly useful? What becomes 
of the air that has been used? These and other questions 
constitute the problem of respiration , the process by 
which the body exchanges its carbon dioxid for oxygen. 

Exercise I. Studies of Respiration 

i. Respiration in plants. Invert one pint milk bottle 
over another pint milk bottle, the bottles being held 
together by a single large cork that projects into the 
mouth of each, as shown in Figure 61. After the cork is 
fitted, take it out and through the center of it bore a hole 
large enough to allow the stem of a young bean plant, 
or other plant, about four to six inches long, to pass 
through it loosely. You will have to split the cork half¬ 
way in to admit the stem of the bean plant. Set up your 
two bottles again. Now set up another pair of bottles 
in the same way, placing a second young bean plant 
within them. 

A. Fill one of the under bottles with fresh well water, 
and fill the other under bottle with well water that has 
been boiled (to get rid of its oxygen) and cooled. Let 
stand for several days. Does a plant do better when 

226 


RESPIRA TION 


227 



Fig. 61. These two bean plants were of the same 
general appearance at the beginning of the experi¬ 
ment; and they were treated alike, except that the 
water supplied to one of the plants contained 
extremely little air. 


its roots are in water containing oxygen, or when its roots 
are in water containing no oxygen? 

B. Toward the end of the experiment in A , set the 
bottles in a dark place for 24 hours. Then take the top 
bottles off carefully, set them right side up at once, and 
pour some clear limewater into each of the two. Quickly 








228 


HYGIENE BY EXPERIMENT 


cover the mouths of the bottles and shake the bottles, so 
as to mix the air and limewater. What gas did your bean 
plants give off at night, or in the dark, as you judge from 
the result of this experiment? 

C. How did the bean plants in your experiments il¬ 
lustrate the process of respiration, that is, the process of 
giving off carbon dioxid and taking in oxygen? 

2. Respiration of fishes. Put goldfish or other small 
fish in a gallon vessel of water that has been boiled and 
cooled. 

A. In what part of a vessel of previously boiled water 
do fish tend to stay, and why do they stay there? 

B. Transfer the fish to a similar vessel of fresh water 
that has not been boiled. Where do fish tend to stay in a 
vessel of fresh water, and why do they stay there? 

C. Let the fish remain for a day or two in the vessel 
that contains the unboiled water. Where do the fish tend 
to stay in a vessel of water they have been in for a day or 
two, and why do they stay there? 

3. The needs of a candle flame. Recalling or repro¬ 
ducing the experiment with the candles in the studies of 
air in Part One, Study Five, explain why a candle 
flame goes out if it is completely covered with a vessel. 

4. Need for oxygen in combustion. Recall your experi¬ 
ments with the burning food and the calorimeter in Part 
Three, Study Thirty-three. What does food require in 
order to make it burn and yield heat? 

5. Human external respiration. Study the diagram, 
Figure 62, and then answer the questions that follow: 

A. What is the gain in the quantity of oxygen in the 
blood that passes through the lungs? 

B. What is the fractional loss of carbon dioxid from 
the blood that passes through the lungs? 


RESPIRA TION 


229 


C. How much more carbon dioxid than oxygen is 
there in the blood, even as it goes from the lungs? 




GASES IN 
BLOOD 
GOING TO 

THE LUNG 5 


T IOO 




% 


GASES IN 
BLOOD 
GOING FROM 
THE LUNGS, 


NITROGENU.o 
2 . 


Fig. 62. The gas content of the blood 
as it enters the lungs and as it leaves 
them. As in Figure 59, it is only the 
percentage of carbon dioxid and the 
percentage of oxygen that are affected. 


D. Carbon dioxid being an impurity in the blood, is it 
proper to say that blood is wholly purified in the lungs? 

E. What, then, would be a truer statement about the 
work of the lungs? 

Exercise II. Your Breathing Organs 

1. Breathing through the nose. Recall or repeat the 
studies of the nose and throat given in Part One, Study 


























230 


HYGIENE BY EXPERIMENT 


Four. What are the six reasons why you should breathe 
through the nose? 

2. Studying a voice box. Get from a butcher the voice 
box or pharynx , and a part of the windpipe or trachea , 
of a hog or other animal, and make an examination of it. 

A. Does the lid of the larynx, called the epiglottis , 
open forward or backward? 

B. Are the vocal cords like two fiddle strings? If not, 
how can they better be described? 

C. How do you think an animal produces voice with 
its larynx? 

3. Studying a windpipe. Examine the windpipe or 

trachea for answers to these questions: 

A. What serves to keep the tracheal tube open for 
breathing? 

B. Why can the tracheal tube be bent so easily? 

C. Into what two tubes does the trachea divide at its 
lower or lung end? 

4. Studying lungs. Examine the trachea, lungs, and 
heart of some animal, such as a chicken, hog, or sheep. 

A. Why do butchers sometimes call the lungs of an 
animal the “lights”? (See this term in the large dic¬ 
tionary.) 

B. Why do the lungs of an animal float when thrown 
in water? 

C. Thrust into the trachea a glass tube of a diameter 
that will fit snugly into the tracheal opening. After 
taking in a full breath, blow the prepared lungs as full as 
possible. How much bigger are a pair of lungs when in¬ 
flated than when not inflated? 

D. Now cut off a lobe of the lung and examine the 
interior of it. If a lung is neither hollow nor solid on the 
inside, how would you describe it? 


RESP1RA TION 


231 


E. If you find little car¬ 
tilaginous tubes (branches 
of a bronchial tube) run¬ 
ning through the inner 
parts of a lung, what pur¬ 
pose do you think they 
serve ? 

5. An artificial thorax. 

Arrange a device such as 
the one shown in Figure 
63, using a cylindrical 
lamp chimney, a long flat 
cork with a small hole in 
it, a short glass tube, a 
small rubber balloon, or 
“squawk,” and a piece of 
flat rubber dam such as 
dentists use. 

A. What breathing 
organ does each of the 
parts represent, as shown 
in the accompanying dia¬ 
gram? Copy Figure 63 in 
your notebook and label 
the parts of the apparatus 
with the names of the 
breathing organs. 

B. How, with the rub¬ 
ber base representing the 
diaphragm , can you get 
air into and out of the 
rubber squawk, represent¬ 
ing a lung? 



Fig. 63. Apparatus for demonstrating 
how the lungs work. 















































232 


HYGIENE BY EXPERIMENT 


Exercise III. Questions for Investigation 

1. What is respiration? 

2. What are the two objects of respiration? 

3. In taking in a breath, through what successive 
organs of respiration does the air pass? 

4. What is the thorax, and what is it for? 

5. What is the diaphragm, and what is it for? 

6. How are the ribs used in breathing? 

7. What organs does the thorax contain? 

8. What becomes of some of the oxygen that goes into 
the lungs with the air? 

9. Where does the carbon dioxid come from that is 
found in the air passing out of the lungs? 

10. Why should you be careful not to get dust into 
your lungs? 

11. Why should the nose be the place for the sense of 
smell? 

12. What is the effect of tobacco smoke on the 
breathing organs? 

13. In the light of the studies you have just made, 
what health habits do you think you should observe 
regarding respiration? 


STUDY THIRTY-SEVEN 

BLOOD AND LYMPH 

Examined with the unaided eye, blood appears to be a 
rather thick, red liquid of uniform substance. Such a 
liquid the ancients supposed it to be, because they had no 
instruments with which to make a minute examination. 
They realized that it is a vital fluid, but they had no 
means of discovering how it served its important pur¬ 
poses. 

It was not until the settlement of the American Colon¬ 
ies was well under way that a Dutch scientist, named 
Leeuwenhoek, made use of the microscope to study 
human blood. Great must have been his astonishment 
when he discovered that blood is about half water, and 
that myriads of tiny circular bodies (corpuscles) float in 
this water. The sight that was so strange in Leeuwen¬ 
hoek’s day we may now see with very little difficulty. 

Exercise I. What Blood Is Made Of 

i. Appearance of blood highly magnified. Place on a 
glass slide a drop no bigger than a pinhead of normal salt 
solution (water and .6 per cent, of common salt). With a 
handkerchief wrap one of the fingers of the left hand from 
the knuckle down to the first joint. Bend the joint and 
with a needle give it a sharp prick near the root of the 
nail. The needle should have been sterilized by dipping it 
in alcohol or holding it for an instant in a hot flame. 
Touch the drop of blood you have just secured, to the 
salt solution on the slide. Quickly apply a clean cover 
glass, pressing it down with the back of a finger nail, 
so as to keep the cover glass free from finger marks. Press 
until there is only a thin layer of blood under the cover 


233 


234 


HYGIENE BY EXPERIMENT 


glass, so thin as to appear more orange than red. Place 
the mounting in a compound microscope as shown in 
Figure 65. Examine the mounting under the lenses that 
magnify about 100 diameters. 

What is the appearance of blood when seen under a 
microscope? 

2. Blood magnified 500 times. Taking the slide used 
in the foregoing experiment, while the blood is still fresh, 
examine for red corpuscles. Use the high-power micro¬ 
scope, magnifying 500 times. These red corpuscles are 
the numerous bodies only slightly tinged with color, that 
float around in a liquid called plasma. The red corpuscles 
are all of the same size and shape, though they may not 
appear so, for they are biconcave discs; that is, they 
are shaped as some peppermint candy discs are — con¬ 
siderably hollowed out at the center on both sides, but 
without a hole through the center. Make drawings of as 
many shapes as appear, and as nearly as possible show 
relative sizes. Note that a human red corpuscle does not 
have a nucleus. If the mounting stands too long, the red 
corpuscles tend to get star-shaped. A new mounting will 
then have to be made, if further examination is needed. 
The red corpuscles carry the oxygen over the body. What 
is the appearance of a red blood corpuscle when seen 
under the microscope? (See Figure 21.) 

3. Seeing white corpuscles. Looking very sharply 
you may see one or two colorless or gray corpuscles that 
are irregular in shape, and granular in appearance. These 
are white corpuscles, the kind that fight germs. There is 
only one to three or four hundred red ones. What is 
the appearance of a white blood corpuscle when seen 
under a microscope? 

4. The clotting of blood. To examine blood in larger 


BLOOD AND LYMPH 


235 


quantities, some fresh blood will be needed. The blood of 
a chicken that has just been killed will serve very well. 
The blood should be collected in a suitable bottle just 
before it is needed by the class. At once divide the quan¬ 
tity of blood into three equal parts, pouring it into three 
small, wide-mouthed bottles. Set one of these bottles 
away in a warm place. Into the second bottle put about 
one-tenth as much of a saturated water solution of epsom 
salts as there is blood. With a common table fork stir 
constantly the blood in the third bottle, occasionally 
wiping off the threads of fibrin that gather on it. The 
stirring should continue until the threads quit forming. 
What makes blood clot? 

5. Studying clotted blood. After the blood is clotted in 
the first bottle, note how the jellylike part draws up in 
the center of the bottle and permits a liquid to gather 
around the outside. This liquid is called serum. 

A. Recalling how the fibrin threads that formed in the 
plasma in the third bottle were taken out on the fork,what 
would you say is the difference between serum and plasma ? 

B. Why did not the blood coagulate in the bottle that 
had the epsom salts in it? 

C. How do you suppose mosquitoes manage to keep 
the blood from clotting around their bills when they 
pierce the skin of an animal and suck blood for some 
minutes at a time? 

D. What is the advantage of the clotting of blood when 
a wound is received? 

6. The chemical nature of blood plasma. Recalling 
that litmus paper turns red when it is put into an acid 
solution and blue when it is put into an alkaline solution, 
test with pieces of blue and pink litmus paper some of the 
blood serum from your prior experiments. 


236 


HYGIENE BY EXPERIMENT 



Fig. 64. A frog properly mounted so that the flow of blood through 
its web may be observed. The mounting should be done care¬ 
fully and humanely, and the cloth should be moist or even wet. 
A frog drinks through its skin. 


Now test the plasma for grape sugar, using the test 
for grape sugar given in Study Thirty-one, Exercise I. 

A. Is blood acid, or alkaline, or neutral? 

B. What evidence have you that there is no grape 
sugar in the blood? 

7. The work of red corpuscles. Take a glass tube and 
exhale air through it into the blood of the second and 
third bottles. 

A. What change in color takes place in blood when 
exhaled air passes through it? 

B. Since the exhaled breath is deficient in oxygen, why 
did the blood change color as it did? 

8. The work of white corpuscles. Turn to Study 
Seventeen, Exercise II, and perform the experiments and 
answer the questions there given, if you have not already 
done so. If you have previously performed the experi- 









BLOOD AND LYMPH 


237 


ments, reread the Exercise, and then answer these ques¬ 
tions: 

A. How do white corpuscles fight germs? 

B. Under what condition will white corpuscles destroy 
germs at all? 

C. What is an opsonin? 

D. What is an antitoxin? 

Exercise II. What Lymph Is 

For this study you will need a live frog of medium size, 
such as any boy or girl can capture. The study will give 
you a chance to get a glimpse of some very small blood 



Fig. 65. A compound microscope in use for studying the circulation of 
blood. Six different magnifications may be made with this instrument 
by shifts of the lenses. The frog should be allowed to hop away as soon 
as he has made his contribution to education. 




















238 


HYGIENE BY EXPERIMENT 


vessels and also the blood and lymph as it appears in the 
web of a frog’s foot. 

1. A frog’s web under a microscope. Provide a thin 
board or shingle about 3 by 8 inches in size. At one end 
of this board make a hole an inch in diameter, and cover 
this hole with a piece of glass held in place by four tacks. 
Wrap a live frog gently with a damp cloth so as to keep 
its skin at all times well moistened. Leave one hind leg 
of the frog free, and mount the frog on the board as 
shown in Figure 64. When mounted, the web of the 
uncovered foot should lie on the glass over the hole and 
be held in place by soft threads tied to two of the frog’s 
toes and then fastened to the end of the board in a way 
to stretch the web gently. 

Lay the web end of the frog mounting on the stage of 
the microscope, and so hold the other end that the web 
will come level under the object lens, as shown in Figure 
65. Now, using the lenses that magnify about 100 diam¬ 
eters, study the numerous little streams of blood, with 
their floating corpuscles, running in various channels 
through the field. These channels are small blood vessels. 
The branched black spots in the field are pigment gran¬ 
ules in the skin of the frog. Remember that the rate at 
which the blood is seen flowing is magnified also. The 
blood, therefore, really flows only one one-hundredth as 
fast as it seems to flow. 

Draw a part of the microscopic field showing the three 
kinds of blood vessels in a frog’s web, and label each 
properly. 

2. The appearance of lymph. In the observations just 
made, the corpuscles were seen floating in the liquid called 
the plasma. Look at the same mounting again and note 
that in the thin parts of the flesh outside the blood vessels 


BLOOD AND LYMPH 


239 


there is a liquid among the cells of the tissue. This liquid 
is called lymph , and it got where it is by oozing out 
through the very thin walls of the finest blood vessels. 
Lymph, therefore, does not generally differ much from 
blood plasma. However, it is present in every part of the 
body outside the blood channels and where there are cells. 
Which of the liquids of the body do you suppose is the 
greater in quantity, the plasma or the lymph, as you 
judge from what you see in the frog’s web? 

Note. When through with the observation called for, care¬ 
fully release the frog and return it to the place where you got it. 
It should not have suffered if you followed directions carefully. 

3. Lymph as commonly seen. In a water blister, you 
have had a chance to observe real lymph. 

A . What is lymph like, as you see it in a water blister? 

B. In what way are tears and sweat somewhat like the 
liquid that comes from a water blister? 

Exercise III. General Questions 

1. What are the parts of the blood? 

2. What is the plasma made of? 

3. What makes the blood look red? 

4. What is the shape of a red corpuscle? 

5. What is the work of the red corpuscle? 

6. How do white corpuscles differ from red ones? 

7. What is the work of white corpuscles? 

8. What are the capillaries? 

9. What is lymph, and what is it for? 

10. Where does lymph come from? 

11. How does lymph get back into general circulation? 

12. What health habits have been suggested to you by 
your studies of blood and lymph; that is, what habits do 
you think would help you to keep up a good quality of 
blood? 



STUDY THIRTY-EIGHT 

THE CIRCULATION OF BLOOD AND LYMPH 

William Harvey, an English physician, is known as 
the discoverer of the circulation of blood in the human 
body. He never saw the blood in actual circulation, ex¬ 
cept as he observed blood flowing from wounds. How¬ 
ever, he judged from what he discovered about blood 
vessels and about the behavior of blood in the body, that 
it must circulate. Dr. Harvey died in 1657, but it was a 
few years after this that the microscope was so far per¬ 
fected that it could be used to observe the finer blood 
vessels and the blood in actual circulation in animal 
tissue. What would Dr. Harvey not have given to be 
privileged to see a sight that modern science and inven¬ 
tion have made easily possible for all! 

Exercise I. The Blood Vessels 

1. Blood vessels in a frog’s web. Mount a frog as you 
did in Study Thirty-seven, and make a closer examination 
of the blood vessels. The very finest blood streams are in 
tiny blood tubes called blood capillaries. Look now for 
two of the largest blood vessels in the microscopic field. 
In one the blood will be seen flowing more swiftly than 
in the other, and in an opposite direction. The first of 
these blood vessels is called an artery , and the second is 
called a vein. 

A. Which kind of blood vessel seems under a micro¬ 
scope to be carrying the blood toward the heart and which 
from it? 

B. A compound microscope reverses its images both 
right and left and up and down. These streams are there¬ 
fore really flowing opposite to their seeming direction. In 


24.0 


CIRCULATION OF BLOOD AND LYMPH 


241 


terms of the direction in which the blood actually flows 
in relation to the heart, what is a definition for an artery 
and what for a vein? 

C. One of these two kinds of vessels divides and sends 
the blood into smaller tubes or capillaries , and the other 
receives its blood from smaller vessels. Which kind of 
blood vessel, an artery or a vein, empties its blood into 
larger vessels and which empties into smaller ones? 

2. The heart. For your next study you need the heart 
of a hog, sheep, or other mammal. If you get this from a 
butcher, be sure to ask for a heart with the “pipes” left as 
long as possible on it, for otherwise he is likely to cut off 
these arteries and veins close down to the heart. The 
arteries stand partly open when empty, and the veins 
flatten down. Find the largest stump of artery there is, 
called the aorta , and the largest veins, called the venae 
cavae, and examine these. Then answer the questions 
that follow. 

A. Which has the thicker wall, an artery or a vein? 

B. Which is straw-colored and which is somewhat 
transparent? 

3. Examining your own veins. Look at your wrist and 
note the blue lines showing the locations of veins. These 
are blue because the walls of the veins make them look so. 
The blood in them is not blue but dark red. Now lay 
your finger across the veins in the wrist, and press the 
blood first toward the palm of the hand and then toward 
the elbow. Which way do you think the blood is naturally 
flowing in the veins you can see on your wrist? 

4. Taking your pulse. To study your pulse, lay the 
back of your left wrist in the palm of your right hand, 
bringing the ends of your second and third fingers 
around until they press over the artery lying deeper than 


242 HYGIENE BY EXPERIMENT 

the veins, and just inside the left bone of the left fore¬ 
arm. What is your pulse rate per minute under the var¬ 
ious conditions set out below? 

A. After sitting quietly for io minutes. 

B. After standing up for some minutes. 

C. Just after running rapidly for a few minutes. 

D. How many pulse beats per minute has a baby? 

E. How many pulse beats per minute has an old man 
or woman? 

5. Locating other pulses. Locate six different places 
over your body where pulse beats can be counted in 
arteries. Where do you find six such pulsating places 
over the body? 

6. Time relation of pulses. Sit with one knee over the 
other, allowing the upper leg to hang freely from the 
knee so as to give the foot a chance to bob with pulsations 
of blood sent out by the heart. Place the fingers of one 
hand over the big artery in the neck on either side of the 
voice box. At which point does the pulse beat seem to 
come first, at foot or neck? Why should it come there 
first? 

7. Time relation of heartbeat and pulse. With the 
ends of the right-hand fingers placed over the space be¬ 
tween the fifth and sixth ribs at a point about two inches 
to the left of the lower end of the breastbone, locate the 
“apex beat” of the heart. With the right hand still in 
position, place the finger ends of the left hand on the 
pulse in the wrist of the right arm. Keep this position 
until you feel a distinct beat through each set of fingers. 

A . Does the apex beat of the heart, or does the wrist 
beat come first? 

B. What do you infer is the relation between heart¬ 
beat and pulse beat? 


CIRCULATION OF BLOOD AND LYMPH 


243 


Exercise II. The Heart and Its Work 

1. The inside of the heart. Take the specimen of heart 
used in the second experiment in Exercise I of this Study, 
and cut its chambers open. 



Fig. 66 . Diagrams of the heart. A shows the action of the valves at the 
expansion of the heart. B shows the action of the valves at the beginning 
of contraction. The action of valves between auricle and ventricle is 
indicated in the diagrams of working models, a and b. 


A. How many chambers has the heart you have stud¬ 
ied? 

B. What are the valves like that are between each 
upper chamber and its corresponding lower one? 

C. Find the three little moonlike valves at the place 
where the aorta leaves the biggest chamber of the heart. 

D. Do the valves in the aorta, where it joins the heart, 
let the blood go to or from the heart chamber? 

E. How do they keep the blood from flowing the 
other way? 

2. Locating your own heart. Locate the lower end of 
your breastbone and then move the finger ends an inch or 
two to the left until you come between the ends of the 















244 


HYGIENE BY EXPERIMENT 


fifth and sixth ribs and can feel the thumping of the lower 
point of the heart against the chest wall. This is the ex¬ 
treme left of the heart, the heart lying like an inverted 
pear, the big end of it being tilted over so it lies behind 
the lower two thirds of the breastbone. About how 
many inches is it from the upper edge of your heart to the 
lower edge? 

3. Studying heart sounds. Place your ear against 
the central part of the heart of some other person. Listen 
closely for the two sounds the heart makes each time it 
contracts. Which sound of the heart is short and sharp 
and which is longer and duller, the first or the second? 

4. How the heart works. If possible, get a glass model 
of a pump, such as can sometimes be found in a physics 
laboratory. If this cannot be done, perhaps a small 
pitcher pump can be examined to show how a pump’s 
valves keep water going in one direction only. Make a 
drawing in your notebook showing what a pump valve 
looks like and how it works. 

5. The course of circulation. The left side of the heart 
pumps blood out over the body through arteries, next 
through capillaries, and then through veins. These in 
turn bring the blood back to the right side of the heart. 
From this point it is pumped through the lungs back to 
the left side of the heart. If the heart is not strong, it 
cannot send enough blood to the lungs to get oxygen to 
distribute over the body. Why do some people feel “short 
of breath/’as they call it, after climbing long stairways or 
running for a little distance? 

6. An artificial pulse. Attach about two feet of 
narrow rubber tubing to the outgoing end of an ordinary 
syringe bulb. To the outer end of this long tube attach a 
glass nozzle that tapers down to a fine point or opening. 


CIRCULATION OF BLOOD AND LYMPH 


245 


Put the receiving and the discharging ends of this ap¬ 
paratus into a pan of water, and cover the middle part 
of the long tube with a cloth or towel. Now set the bulb 
in action and put your fingers on the cloth over the tube 
as the waves of water are made to pass through the tube. 
By varying the action of the bulb, can you imitate a 
strong pulse, a weak pulse, a sharp pulse, a dull pulse? 
Just how do you squeeze the bulb so as to instate a strong 
pulse? A weak pulse? A sharp pulse? A dull pulse? 

7. The lack of pulse in veins. Press down on the 
middle part of the rubber tube so as to let only a very 
small amount of water pass through. 

A. In which part of the tube is there now a pulselike 
action? 

B. Why does not the other part have a pulselike 
action? Explain fully why there is no pulse in veins. 

8. Elastic and hardened arteries. Keeping exact 
account of the time it takes to do it, drive the water 
through the tube by strong, regular pulse strokes until 
you have filled a tumbler at the discharging end. Now 
take off the long rubber tube and replace it with a glass 
tube of similar diameter and length. Attach the glass 
nozzle of the rubber tube to the outer end of the long 
glass tube by a suitable rubber tube. Again timing the 
process, fill the glass and note the difference in effort and 
time. 

A. How much longer did it take to fill a glass with 
water pumped through a glass tube; and which was the 
harder work, pumping through the glass tube or through 
the rubber tube? 

B. Why was it harder to pump through the one tube 
than through the other tube of the same size? 

C. Why does one who has “hardening of the arteries” 
also have high blood pressure? 


246 


HYGIENE BY EXPERIMENT 


9. Review. For further experiments on circulation, 
see Part One, Study Eight. 

Exercise III. Questions for Investigation 

1. Why does blood have to be kept circulating through 
your body? 

2. What is the work of your heart? 

3. What are the names of the cavities in your heart? 

4. How does the blood get from the arteries over to 
the veins? 

5. What are the capillaries for, besides connecting- 
arteries with veins; that is, what is the special business of 
capillaries? 

6. Through what successive vessels would a drop of 
blood pass in going from the left auricle around to the 
right auricle? 

7. Through what vessels would a drop of blood have 
to pass in getting from the right ventricle around to the 
left ventricle? 

8. What is “hardening of the arteries” and what are ' 
some of its causes ? 

9. How do disease germs sometimes affect the heart? 

10. How does too much exercise sometimes injure the 
heart? 

11. What exercise is proper for the heart, and what is 
improper? 

12. How does tobacco injure the heart? 

13. How do headache remedies affect the heart? 

14. How do alcoholic patent medicines affect the 
heart? 

15. How may the heart sometimes suffer irritation 
from the stomach? 

16. What health habits would favor good circulation 
and heart action? 


STUDY THIRTY-NINE 

COMMON COLDS AND HOW TO AVOID THEM 

Colds are very common ailments, and they probably 
get their name from the fact that they so often develop 
after people get chilled. However, colds are really due 
to two conditions other than chilling. One of these is a 
disturbed circulation. There are some interesting facts 
about blood circulation that people do not commonly 
take into account in connection with colds; but by the 
use of apparatus such as is shown in Figure 67 these facts 
can be made clear. 

The apparatus requires the use of a carpenter’s saw¬ 
horse and a balancing plank about 6 feet long and about 
12 inches wide. To the underside of each edge of the 
balancing plank and crossing its middle, fasten flat 





Fig. 67. Apparatus for studying the effect of cold on the distribution 
of blood in the body. An old door has been used for the teeter board, 
and a big rock furnishes the weight. 

247 














248 


HYGIENE BY EXPERIMENT 


pieces of iron and across their centers file a broad notch 
that will be just under the central cross line of the plank. 
Then on the top of the sawhorse fasten down two large 
three-cornered files or other objects that will form knife¬ 
like edges to support the balancing plank. When the 
plank is in position, suspend under it a box by wires 
from each corner of the board, and fill the box with bricks 
or iron enough to bring the center of gravity just below 
the centers of support when a pupil lies on the board. 

Exercise I. Making Some Experiments with Blood 

Circulation 

1. The effect of cold on the distribution of blood. 

When the apparatus described above is set up out of 
doors on a cold day and is ready for use, you must first 
let a healthy boy who does not easily catch cold, balance 
himself on it as shown in Figure 67, just after he has 
come out of a warm room. Fasten a block on the plank 
against the head and against the feet of the boy, to mark 
the exact place where he lay when warm. If necessary, 
secure any final balancing by the addition of small weights 
at either end of the plank. At best, there will be a slight 
teeteringdue to breathing, the muscles of breathing thrust¬ 
ing the abdominal contents back and forth somewhat. 

When the apparatus has been balanced satisfactorily, 
let the pupil lie on the plank until he begins to feel rather 
cold. If the apparatus meanwhile gets out of balance, 
use a spring hand scale to pull it into balance, at the end 
of the experiment, placing the hook on one side of the 
board at the point just opposite the center of the breast¬ 
bone of the pupil. Note the reading of the scale when the 
board is just brought into balance. 


COMMON COLDS AND HOW TO AVOID THEM 249 

A. According to this reading, how many ounces of 
blood have passed upward from the lower limbs? 

B. Find from your dictionary the meaning of the 
word congestion and write it in your notebook. 

2. Five kinds of congestion. As a background for the 
understanding of colds we need to know the difference 
between what is called active congestion and what is 
called passive congestion. To demonstrate active con¬ 
gestion, take an ordinary syringe bulb and pump it very 
fast and see how the delivery tube becomes congested. 
To demonstrate passive congestion, pump slowly, but 
narrow the outlet of the delivery tube by pinching it 
down to a very small opening near the end. In active 
congestion the blood is driven by the heart into the con¬ 
gested part of the body. In passive congestion the blood 
is massed in the congested region because the outlets in 
that part have been somewhat stopped up. 

A. What kind of congestion is blushing? 

B. What kind of congestion comes when you have 
tied a string rather tightly around your finger? 

3. Active congestion. Cold drafts or chilling are the 
means by which active internal congestion is ordinarily 
set up in the human body. As the second necessary con¬ 
dition for colds, germs must be present in the breathing 
passages. The congestion of blood, straining the capil¬ 
laries in the air passages, now brings a lot of white cor¬ 
puscles to the surface of the passages. These white 
corpuscles set to devouring the many germs; and accumu¬ 
lated dead corpuscles compose, in good part, the matter 
that stuffs your nose up when you have a cold in the 
head. To counteract this sort of cold, you need to have 
your system trained to throw back the blood to the 
surface from the inner parts of the trunk. 


250 


HYGIENE BY EXPERIMENT 


A. What is the effect on the training of the heart to 
counteract congestion, of cold baths in the morning, of 
exercise, of open-air sleeping, and of exposure to varying 
temperatures through the day? 

B. If your face gets red when you are out in the cold 
in the winter time, how does this show that your heart is 
well trained? 

C. What is the advantage of having abundant blood 
sent to the face in such a case? 

4. Passive congestion. Passive congestion in the 
human body is caused by an unusual accumulation of 
germs along the air passages. As the white corpuscles 
now travel out to devour the germs, they impede the flow 
of blood in capillaries, and secure a congestion of blood in 
a passive way. Presently a condition results like that 
described in the preceding paragraph. 

A. Why may you catch a cold if you frequent badly 
ventilated and crowded halls or rooms? 

B. How is the continuous breathing of air that is 
warm and dry likely to affect the lining of the air passages? 

C. What would be likely to happen at such a time if 
one were exposed to germs of cold? 

D. Why are people whose noses are somewhat stopped 
up with adenoids or irregular bones, more liable to colds 
than other people? 

E. How is it that if one works in a very dusty place, 
as around a threshing machine, he is particularly liable 
to catch a cold in the head? 

5. Inflammation. If you have had a boil or other sore 
spot, try to recall whether that spot was warmer than 
the surrounding parts. Consider whether the spot was 
puffed out or swollen and was redder than usual. Such 
a congestion of blood is called an inflammation. Carefully 


COMMON COLDS AND HOW TO AVOID THEM 251 

note both the spelling and the pronunciation of the word. 

A. What are the four marks or characteristics of an 
inflammation? 

B. Remembering that inflammations are generally 
due to the presence of germs, why should a good deal ol 
blood be brought to the infected spot? 

C. Why is “catching cold” a good deal like “getting” 
boils? 

Exercise II. Questions for Investigation 

1. What are epidemic colds and chronic colds? 

2. Why are a warm bath and sweating beneficial in 
case of a cold, if care is taken to avoid any chilling? 

3. Why will spraying the nose with an antiseptic help 
to prevent colds? 

4. Why should you see to it that your upper air pas¬ 
sages are kept free and open? 

5. Why will the inhaling of cold air, the skin being 
kept warm, help to prevent colds? 

6. How will the regular practice of keeping the bowels 
open help to prevent colds? 

7. How will the regular taking of cold baths help to 
prevent colds? 

8. Why should you train yourself to endure drafts of 
air that are not too cold or too strong or too long con¬ 
tinued? 

9. What is catarrh? 

10. What is bronchitis? 

11. What are some diseases that may follow neglected 
colds? 

12. What habits must you practise so as to keep from 
catching colds easily? 


STUDY FORTY 

THE SKIN AND BATHING: CLOTHING 

“Clothing makes the man” is an old saying that has 
enough truth in it to give it some point. Likewise, it is 
at least a half truth that a wholesome and attractive skin 
makes the individual. Certainly the skin proclaims the 
individual in more than one way. It is said that Helen 
Keller, the blind and deaf genius, is able to recognize 
her acquaintances accurately without touching or seeing 
or hearing them, and sometimes even without sensing 
the peculiar jar of their footsteps. You may guess how 
she does it. 


Exercise I. The Skin 

1. Thickness. Pinch up a fold of skin on the back of 
the hand and decide how thick you think the skin is at 
that place. Record this judgment in your notebook. 

2. Microscopic appearance. Examine the back of 
your hand with a hand lens, which is also known as a 
“simple microscope.” Next, examine the palm of the 
hand with the lens. 

A . What does the skin on the back of your hand look 
like? 

B. How does the skin on the palm of the hand differ 
in appearance from that on the back of the hand? 

3. Sweat pores. Using a simple microscope again, look 
at the palm of the hand when it is a bit sweaty. Hold the 
hand in a strong light while making the examination. 
If you look very sharply, you should see little glistening 
spots along the top of one of the ridges and about as far 
apart as the ridge is wide. What makes the little glisten¬ 
ing spots? 

252 


THE SKIN AND BATHING: CLOTHING 


253 



Fig. 68 . At the “swimmin’ hole.” These schoolgirls are combining bath¬ 
ing and recreation; and, under safe conditions, they are learning to swim. 


4. Scar tissue. Examine a scar on the skin some¬ 
where. In what three ways is scar tissue different from 
true skin? 

5. Thumb prints. After pressing the thumb of the 
right hand down on an ink pad such as is used in printing 
with rubber type, make a print of the face of the upper 
half of the thumb in your notebook. Get several of your 
classmates to make prints there also, until there is a 
complete row across the page. What use is made of finger 
prints, and why are they so reliable for their purpose? 

Exercise II. Uses of the Skin 

1. Protection. The outer layer of the skin we found 
to be made up of a dead layer of horny cells. 

A. What purpose can the horny layer of the skin serve 
with respect to germs? 













254 


HYGIENE BY EXPERIMENT 


B. Of what value is skin with respect to the lymph 
under it? 

2. Seat of sensations. The skin contains the nerve 
structures for four kinds of sensations. What are these 
sensations? 

3. Absorption. If you rub some liniment on the skin, a 
very little bit of it may get through. What slight use may 
the skin serve if medicines are rubbed on it? 

4. Respiration. The surface that is thrown open to air 
inside one of your lungs is more than fifty times as great 
as the surface of your skin. How much of your respira¬ 
tion may go on through the skin? 

5. Regulation of body temperatures. One of the very 
important functions of the skin, as will be made clear 
later, is helping to keep the temperature of the body at 
98.6° Fahrenheit. What are five different uses of the skin, 
counting the skin sensations as only one use? 

Exercise III. Bathing and the Need for It 

Recall or repeat the work of Study Nine in Part One. 

Exercise IV. Caring for Finger Nails and Hair 

Recall or perform the work of Study Ten. 

Exercise V. Clothing in Relation to the Skin 

Recall or repeat the work of Study Eleven. 

Exercise VI. General Questions 

1. Why is the surface of the body such a favorable 
place for the germs of decay to multiply? See Study 
Fifteen, Exercise II. 

2. What is the primary reason why you should bathe? 

3. How often, therefore, should you bathe? 


THE SKIN AND BATHING: CLOTHING 


255 


4. What kind of bath will open the sweat pores of the 
skin; that is, start perspiration? 

5. Will these pores remain open after you quit per¬ 
spiring? 

6. What kind of bath will close the sweat pores of the 
skin; that is, stop perspiration? 

7. After you go where it is warm or after you begin to 
exercise, will the pores remain open? 

8. What really opens and closes the pores of the skin 
— the temperature or the bathing? 

9. What is the effect of a cold bath on the distribution 
of blood? 

10. What is the effect of a warm bath on the distribu¬ 
tion of blood? 

11. What is the effect of a lukewarm bath on the dis¬ 
tribution of blood? 

12. At what time of day may you best take a daily 
bath, if you do not work amid dirty surroundings? If 
you do work amid dirty surroundings? 

13. What is the primary reason for wearing clothing? 

14. What are three uses of underclothing? 

15. What are four reasons why mesh-woven cotton 
is better for underclothing than wool? 

16. Why should you put on extra wraps when out of 
doors on a cold day? 

17. Why should you take off these extra wraps and 
overshoes in the house, or where it is dry and warm? 

18. What should be the general shape of shoes? 

19. What are two serious objections to high-heeled 
shoes? 

20. What are some habits that will help to keep the 
skin in the best of condition at all times? 


STUDY FORTY-ONE 

VENTILATION AND BODY HEAT 

There is a widespread notion that we need fresh air 
in a living room primarily for breathing purposes. This 
idea, like a great many other ideas regarding the work 
and the needs of the human body, is only partly true. 
There are two other even more important reasons why 
a living-room ordinarily needs to be ventilated, and our 

present Study will attempt to make them clear. 

# m 

Exercise I. Gaining and Losing Heat 

i. Heat production in the body. Put some drops of 
sulfuric acid in a small glass of water. Being exceedingly 
careful not to let more than a few drops go in at a time, 
keep on adding drops slowly until you feel the glass 
getting distinctly warm. There is a chemical action 
going on between the sulfuric acid and the water. Always 
where there is chemical action, heat is produced. This 
kind of action goes on in the muscles and glands of the 
body, and especially in the liver. 

A. Why does the blood get warmed in the liver to 
the highest temperature anywhere in the body (i07°F.)? 

B. Why do contracting muscles get warm? 

C. Why do you need so much more oxygen when you 
exercise vigorously? 

D. Why do you get so warm when you exercise vio¬ 
lently? 

E. Why do you need more cover or clothing to keep 
you warm when lying down than you do when standing 
up or actively working? 

F. Where is the heat produced in your body when 
you are asleep? 


256 


VENTILATION AND BODY HEAT 


257 


2. Conduction, convection, and radiation of heat. 

Heat is lost and gained directly from and to the body by 
three different processes. One of these processes of heat 
transfer is illustrated in the case of holding one end of a 
stove poker in the fire till the handle gets hot. The heat 
here travels from one tiny particle of iron to the next one, 
and so on. The process by which heat travels over the 
successive particles of a substance is called conduction. 

The second of these processes of heat transfer is called 
convection. This is the process that goes on when a pan 
of warer is heated over a flame. The particles of water 
nearest the source of heat are made hot. These heated 
particles rise to the top, while the colder particles fall to 
the bottom of the pan, where they become hot. By a 
circulation of particles, the mass becomes heated. This 
method of heat transfer is also illustrated in heating 
with a hot-air furnace. Air comes in contact with the 
heating dome of the furnace, where it takes on heat. 
It then rises through a pipe to a cold room, bringing its 
heat with it into the room. 

The third process of heat transfer is a peculiar one, for 
here the heat travels, not on matter, but on the ether, 
which is supposed to pervade all space, and is believed to 
be a carrier of waves of heat and of light. The process is 
called radiation. Perhaps this will help you to under¬ 
stand why the word radiator is appropriate to some pieces 
of heating apparatus. 

A. If you put your hand on a warm iron, by what 
process does the hand gain heat? 

B. If you stand in sunshine, by what process does your 
body get warm? 

C. If you sit in a warm draft of air, by what process is 
the heat brought to your body? 


258 


HYGIENE BY EXPERIMENT 


3. Automatic regulation of body temperature. The 

blood is the great carrier of heat over the body, getting its 
heat, as was said before, from the active muscles and 
glands. When the temperature of the surrounding air is 
more than 70° F., the greater part of your blood is near 
the surface of the body. When this temperature is be¬ 
tween 68° F. and 70° F., the blood is about evenly dis¬ 
tributed near the surface and deeper in. When this 
temperature is below 68° F. the blood tends to leave the 
surface and goes deeper in. The blood is withdrawn from 
the surface as the temperature is reduced in order to 
keep from giving off so much heat directly to the air 
around. The skin then gets colder, and the muscles go to 
work of their own accord so as to produce additional 
heat. But they sometimes contract irregularly, and that 
is why one shivers. 

A. Why is a surrounding temperature of 68° to 70° 
best for one who is not vigorously working? 

B. Why does the skin get so pale when it is very cold? 

C. Why are the veins of the skin so full on hot days? 

D. Why does your face get red when you are standing 
near a hot stove? 

4. Water evaporation in moving air. Because the 
human body perspires only to get rid of heat, it becomes 
important to get at some of the facts about evaporation. 
Put two or three drops of water in each of two saucers, 
keep them in a moderately warm room, fan one of them 
so as to keep the air in motion over it, and note the time 
it takes the water in each to evaporate. 

A. Why do fanned drops of water dry up more 
quickly than drops not fanned? 

B. What was the difference in the time required for 
the two quantities of water to evaporate? 


VENTILATION AND BODY HEAI' 


2 59 


5. Effect of evaporation on surrounding temperatures. 

To study an important effect of evaporation, take an 
ordinary dairy thermometer, insert its mercury bulb in a 
small bottle of ether or gasoline, and let stand for a few 
moments. Now take the thermometer out, read it 
quickly, and then watch what the mercury column does 
while the ether is evaporating from the bulb. 

A . What was the reading of your thermometer at the 
moment it was taken from the ether? 

B. Through how many degrees did the mercury 
change? 

C. Why did the mercury column then go back to where 
it stood at first? 

6 . Sensory verification. Pour a few drops of ether or 
gasoline on your hand. 

A . How does your hand feel when ether or gasoline is 
poured on it? 

B. What is the effect on temperature when a liquid is 
evaporating? 

C. What purpose seems, therefore, to be served by 
your perspiring? 

Exercise II. Some Studies of Ventilation 

1. Two primary reasons for ventilation. Provide a 
cabinet such as is shown in Figure 69 or in Figure 70. 
After airing it out well, and after noting the temperature 
of the room, enter the cabinet. Unless there is an electric 
fan in the cabinet, take along a palm-leaf fan. Close the 
door. For the purpose of this study, the cabinet may be 
called a ventilation cabinet. Remain in the cabinet until 
the temperature within is about 8o° F., or preferably 
higher, certainly until you are uncomfortably warm and 
sweaty, and have a feeling of closeness in the air. At this 


260 


HYGIENE BY EXPERIMENT 


Fig. 69. An ordinary schoolroom closet converted 
into a ventilation cabinet. Note the electric fan and 
the way in which the pupil’s head fills the opening. 
She gets outside air for breathing, yet no air from 
the outside can get mixed with the air inside the 
closet. 



time take the temperature of the air in the cabinet by 
means of a dairy thermometer hung down through a 
small hole in the top of the cabinet or perhaps through a 
hole in the side. Now stir up the air vigorously with the 
fan for a minute or less, in order to break up the vapor 
jacket of air next your skin, meanwhile pulling the 


























VENTILA TION A ND BOD Y HEA T 


261 


clothing away from your body as much as possible. 
Again take the temperature inside the cabinet, and 
record any change in temperature the thermometer may 
show. 

A. What temperature change did you experience in 
your ventilation cabinet experiment when the air inside 
was stirred? 

B. Why did the change seem to you much greater 
than the thermometer showed it to be? 

C. Why did the breaking up of the jacket of moist air 
next the skin serve to cool you? 

D. What is an important reason why the air of a living 
room needs to be kept stirring? 

E. From what you noticed about the air in the cab¬ 
inet, as you came out, give another reason why the air of a 
living room needs to be changed and why one should 
bathe. 

F. What do you think is the chief source of bad air in 
a crowded room, as you judge from your experience on the 
way out of the cabinet? 

G. Judging by the effect of the fanning, what is the 
most important reason why a living room needs to be 
ventilated? 

H. What is a second important reason why a room 
needs to be ventilated? 

2. A third reason for ventilation. Turn back to the 
end of Study Four and find how many cubic inches of 
air you breathe in an hour. Since one twentieth of each 
breath corresponds to the amount of oxygen you use up 
every time you breathe, find this amount in cubic inches, 
and multiply it by the number of breaths you take in 
an hour. 

A. How many cubic inches of oxygen do you need 
in an hour? 


262 


HYGIENE BY EXPERIMENT 


B. How big a square of cardboard would make one 
side of a cubic box that would contain a supply of 
oxygen for you for an hour? 



Fig. 70. A cabinet built especially for the ventilation 
experiment. The floor is adjustable so that people of 
different heights may stand in the cabinet. 

3. The oxygen supply in a bedroom. If you were shut 
up in an air-tight bedroom measuring 10 x 10 x 8 feet, 
how long would it be until you had used up all the 
oxygen available? You remember that you found close 
to one fifth of ordinary air to be made up of oxygen. 



































































































VENTILA TION A ND BOD Y HE A T 263 

Your closed bedroom would thus contain about 160 
cubic feet of oxygen. Still, you are so constructed that 
you can never take up more than about two fifths of the 
oxygen found in ordinary air. In your small bedroom, 
therefore, only about 64 cubic feet, or 110,592 cubic 
inches of oxygen would be available. Dividing this by 
the number of cubic inches of oxygen you found that 
you need in an hour, how many hours do you find that 
you could stay in a bedroom measuring 10 x 10 x 8 feet, 
before you would need more oxygen? 

4. A fourth reason for ventilation. But there is a 
condition that would make it necessary for you to leave 
the room long before you used up the available oxygen, 
and that is the accumulation of carbon dioxid. At the 
time you are using up the oxygen from the inhaled air 
you are adding nine tenths as much carbon dioxid to 
take its place in the exhaled air. How much carbon 
dioxid do you give off in an hour? 

5. That bedroom again. Careful experimentation by 
physiologists has shown that one can stay in a room 
until the quantity of carbon dioxid in it is raised to 
3 per cent, of all the air in the room. In the case of the 
bedroom we have been considering, this will be 24 cubic 
feet or 42,417 cubic inches. Dividing this by the number 
of cubic inches of carbon dioxid you give off in an hour, 
find the number of hours you could stay in the bedroom 
before too much carbon dioxid accumulated. 

A. How many hours is this? 

B. Which condition, an excess of carbon dioxid or a 
shortage of oxygen, would the sooner make you call for 
fresh air? 

6. Carbon dioxid in your schoolroom. Calculate how 
much carbon dioxid could be endured by one person in 


264 


HYGIENE BY EXPERIMENT 


your schoolroom, figuring this at 3 per cent, of the total 
cubic inches of space. Divide your result by the sum 
of the cubic inches of carbon dioxid given off in an hour 
by all the pupils together. How long could all of you 
stay in your schoolroom before you would have to have 
air from the outside? 

7. The four reasons for the ventilation of a living room. 

Recalling your conclusions from the ventilation-cabinet 
experiment, you know you need to have a room ven¬ 
tilated long before there is too little oxygen or too much 
carbon dioxid. Set down in your notebook, in the order 
of their importance, the four distinct reasons why a 
living room must be ventilated. 

8. Securing ventilation. You should now find out the 
fundamental principle for any system of ventilating a 
room. Bore two holes in the lid of an empty cigar box. 
Let them be about 2 inches apart, and an inch in diam¬ 
eter. Place a short lighted candle under one of the holes, 
close the lid tightly, and then set a lamp chimney over 
each of the holes. A pasteboard tube an inch or so in 
diameter and 6 inches long may be substituted for the 
lamp chimneys. By means of smoke from an extin¬ 
guished match, discover which way the air is moving at 
the top of each chimney. If the weather is cool outside, 
open the window sash about two inches at the bottom 
and as much at the top. Try placing smoke or chalk 
dust at each of the window openings, to see which way 
the air currents run. 

A. Which is heavier, cold air or warm air? 

B. How is air made to circulate in a room? 

Exercise III. Questions for Investigation 

1. How do the sweat glands help to regulate the body 
temperature? 


VENTILA TION A ND BOD Y HEA T 265 

2. In what two ways do the small blood vessels of the 
skin help to regulate the temperature of the body? 

3. What is the danger in chilling the body very much? 

4. Why should one be careful not to overheat the 
body? 

5. How does alcohol affect the body temperature? 

6. What is the exact percentage of oxygen in ordinary 
air? 

7. What fraction of the oxygen in air does the blood 
in the lungs take up at a breath? 

8. How low a percentage of oxygen may there be in 
air that will still permit you to live, provided there is not 
too much carbon dioxid in it? 

9. Why is it more important that you should concern 
yourself about the quantity of carbon dioxid in breathed 
air than about the quantity of oxygen? . 

10. What is a poison? 

11. Some books say that carbon dioxid is poisonous; 
but is this really so? 

12. Why is very dry air injurious to the lungs? 

13. What is the best temperature for a living room? 

14. Why does the air in a living room need to be kept 
in motion? 

15. How can you ventilate a room and still avoid a 
strong draft? 

16. What is the chief cause of disagreeable odors in 
crowded rooms? 

17. What is an open-air school? 

18. What is the advantage of outdoor sleeping? 

19. What are some important habits to form with 
respect to body heat and ventilation? 


STUDY FORTY-TWO 

SOURCES, FORMS, AND EXITS OF BODY WASTE 

Can you ever completely destroy anything? The 
answer to this question will depend on what you under¬ 
stand the word “destroy” to mean. You have found in 
your studies of respiration that when a candle burns, the 
candle slowly disappears as a candle. But you also 
found that something else was being made as the candle 
burned: namely, carbon dioxid. 

No doubt you have seen moisture gather on a lamp 
chimney when the cool chimney was first put on after the 
wick was lit. The moisture was made by the flame, and 
it showed on the chimney as long as the chimney re¬ 
mained cool enough to condense it. Now, both tallow 
and kerosene are made from carbon, hydrogen, and oxy¬ 
gen. Carbon dioxid is made from atoms of carbon and 
oxygen; and water is made from atoms of oxygen and 
hydrogen. The atoms out of which tallow and kerosene 
are made are not themselves destroyed in the burning 
process; but the original substances disappear in the 
process of the production of new substances. 

Similarly, the food that you eat undergoes chemical 
changes within your body, and it will be interesting to find 
out what these changes are. 

Exercise I. The Sources of Foods 

i. The difference between an atom and a molecule. 

For your first study you need a number of grains each of 
three kinds of seeds — as wheat, popcorn, and rice. 
Assume that each grain of rice represents a particle, or 
atom, of oxygen; that each wheat grain represents an 
atom of carbon; and that each popcorn grain represents 

266 


BODY WASTE 


267 


an atom of hydrogen. Paste together one wheat grain and 
two rice grains. This combination, or compound , will 
represent a particle, or molecule , of carbon dioxid. Make 
twelve such representations of molecules of carbon dioxid. 

In similar fashion make an illustrative molecule of 
water out of a grain of rice (representing an atom of 
oxygen) and two grains of corn (representing two atoms 
of hydrogen). You will need ten such “molecules” repre¬ 
senting water. In your work with these “molecules” the 
paste or glue represents the energy, or power, with which 
the atoms of molecules are held together. What is the 
difference between an atom and a molecule? 

2. Storing energy in complex molecules. On the left 
side of a piece of paper lay down together 6 of your “mole¬ 
cules” representing carbon dioxid, make a plus mark at 
the right of this pile, and to the right of the plus mark lay 
down 5 “molecules” representing water. Now make the 
sign of equality to the right of the “water.” Take the 6 
remaining “molecules” representing carbon dioxid and the 
5 representing water, and, by the use of more “energy” 
(paste), make of these 11 simple “molecules” a single 
complex “molecule.” 

Pick out from the mass of this single complex molecule, 
12 of its “atoms” of “oxygen.” What you have left is a single 
“molecule” of “starch.” Lay the “starch molecule” to the 
right of your equality sign, make another plus mark, 
and then lay to the right again the twelve “oxygen atoms” 
in six pairs. The whole of this now represents what is 
called a chemical equation. If 6 CO 2 + 5 H 2 0 represents 
the first half of the equation, how will you write out the 
whole equation? 

3. Where starch gets its energy. To make your 
chemical equation entirely true to all the facts, you would 


268 


HYGIENE BY EXPERIMENT 


have to write it 6 C 0 2 + 5 H 2 0 + energy = (what you 
wrote before to finish the equation). The significant 
point about this is that when a large or complex molecule 
is made from a few simple ones, it takes additional energy 
(represented by your paste) to do it. 

Study Figure 71 and note especially the leaf labeled 



Fig. 71. The life functions of a plant. A plant supplies 
its needs largely from the air. The leaves serve as lungs, 
and also as a place for the manufacture of food. 

















BODY WASTE 269 

starch-making, and from it find answers to the following 
questions: 

A. What is the complete equation for the making of 
starch? 

B. What is the source of the energy for the making of 
starch in nature? 

C. What is the source of the carbon dioxid used by a 
leaf? 

D. What is the source of the water used by a leaf? 

4. Proof that sunshine is necessary in starch making. 
Take a potted plant with thin leaves, such as a nastur¬ 
tium, and in the center of one leaf pin together the parts 
of a divided cork as shown in Figure 72. The cork is to 
keep the sun from shining on the part of the leaf it covers. 
Make the mounting at the beginning of a day of sunshine, 
and in the evening remove the cork and the leaf. Put the 
leaf at once into a cup of denatured alcohol and let stand 
for half an hour, until the green substance in the leaf is 
dissolved out. The leaf can then be kept until you are 
ready to apply the starch test to it, the next step in this 
experiment. When ready, dip the leaf in some tincture of 
iodin and note the distribution of starch in the leaf. 

A . What did your starch test show as to the distribu¬ 
tion of starch in the leaf experimented with? 

B. Why was the starch missing at the one spot? 

C. What three things are necessary in the making of 
starch? (See Figure 71.) 

D. Why do not the grains on growing corn ears fill 
very well with starch in seasons when it is cloudy or 
rainy in late August and early September? 

5. How energy is got from starch. You have now 
learned that it takes energy to make starch. Indeed, 
starch is not unlike a wound-up watch spring, for it con- 


27 o 


HYGIENE BY EXPERIMENT 



Fig. 72. A nasturtium plant with one leaf in preparation 
for the starch test. A bit of shingle furnishes the support 
for leaf and cork. 




tains stored-up energy. You eat starch to get its energy 
or power. This energy you use in producing muscular 
contraction to effect various movements. Of course, the 
starch is changed to grape sugar (see Study Thirty-two) so 
it can be carried around by the blood to the muscles, where 
it is again made into a kind of animal starch, called 
gly c °g e n, and stored for use. The energy you get from 
it, when finally it is used, was originally sunshine, as you 
saw from the fourth experiment in this study. 

To get this energy turned loose in your muscles you 
must have some oxygen to take hold of the stored starch 
grain and break it up into carbon dioxid and water, thus 







BODY WASTE 


271 


releasing the energy. The chemical equation that would 
show this is the same one you had for the answer to A 
under the third experiment, only the part at the left of 
the equality sign must change places with the one at the 
right of it. 

A . What is the chemical equation for the breaking up 
of starch in the human body? 

B. Why is air as important for you as food? 

C. What are the two distinct reasons why you breathe ? 

6. The composition of a molecule of fat. In somewhat 
similar fashion you can make a study of fat. Consider a 
common kind of fat, such as the one that gives the pecu¬ 
liar flavor to butter. This fat is called butyrin , and it is 
made up of 15 carbon atoms, 26 hydrogen atoms, and 6 
oxygen atoms (Ci 5 H260) 6 . If you recall your work with 
the cereal grains to represent the atoms of a grain of 
starch, you will see that more extra energy, represented 
by paste, would be necessary if you were to try to follow 
the same procedure in representing a molecule of fat. 

A. Turning to the second exercise in Study Thirty- 
three, what do you find to be the heating power of an 
ounce of butter as compared with that of an ounce of 
starch? 

B. Why should fat yield so much more energy when 
burned than starch does? 

7. Composition of a molecule of protein. Protein mole¬ 
cules are still more complex than either carbohydrates or 
fats, mainly because they are made of more kinds of 
atoms or elements. In addition to carbon, hydrogen, and 
oxygen, a protein molecule always contains nitrogen, 
and then various other atoms, such as phosphorus, sul¬ 
fur, and iron. Thus, you can see that when a protein 
molecule goes to pieces in the human body, it gives up 


272 


HYGIENE BY EXPERIMENT 


substances besides simply carbon dioxid and water. One 
of these substances is hydrogen sulfid , the gas that makes 
rotten eggs smell so bad. There are a number of other 
forms of waste from proteins, but they are too complex 
and varied for you to consider here. Why do decaying 
proteins smell so much worse than decaying carbo¬ 
hydrates or fats? 

Exercise II. The Forms of Body Waste 

1. Carbon dioxid as a form of waste. There are only 
three major forms of body waste; but there are many 
minor forms. Carbon dioxid is one of the three major 
forms, and it comes from each of the three principal 
kinds of organic foods you have just been studying. 
In answering the following questions, keep in mind 
what you have just learned; and recall your studies of 
respiration in Study Thirty-six. 

A. What are the three kinds of primary foodstuffs, 
each of which yields carbon dioxid when broken up in 
the body? 

B. What is the appearance of carbon dioxid? 

C. What organs remove excess carbon dioxid from 
the body? 

D. Why would you die if you were to get into a room, 
or a well, or a vat, where the air contained a large pro¬ 
portion of carbon dioxid? 

E. How does the carbon dioxid get around to the 
lungs from the muscles and glands and other tissues, 
where it is originally made. 

2. Water as a form of waste. Water is the second of 
the three major forms of body waste. You wonder, per¬ 
haps, why water should be a form of waste, since you 
know that it is one of the substances the body most 


BODY WASTE 


273 


needs. It is true that water is taken into the body in 
considerable quantities, but its main purpose is to act 
as a carrier for other substances. It forms nine tenths of 
the liquid part of the blood, and an equal proportion of 
the lymph among the cells. It is present also in the proto¬ 
plasm of which the cells of the body are made. Indeed, 
the bod} 7 as a whole is nearly seven tenths water. 

In the course of a day, about a pint of water is made 
in the body when foods break up in the tissues; but this 
is not enough to do the carrying of dissolved food and 
waste, and more water has to be supplied. 

Water is a waste material only when it is needed to 
carry off waste, or when it is given off by the body for 
other purposes, as to moisten the air one breathes or to 
reduce the body temperature through perspiration. 

A. What are the three primary foodstuffs that yield 
water as they break up in the body? 

B. How much water should you drink on a moder¬ 
ately warm day? 

C. When should most of the water be drunk, at meal 
times, or between meals? 

D. What two organs, besides the kidneys, take water 
out of the blood and eliminate it from the body? 

3. Urea as a form of waste. The third major form of 
body waste is a substance that has not been spoken of 
before. It is made from broken-down proteins. A mole¬ 
cule of it is composed of 1 carbon atom, 1 oxygen atom, 
2 nitrogen atoms, and 4 hydrogen atoms (CON 2 H 4 ) and 
is called urea. The liver is the organ that makes this 
urea. The liver throws the urea into the general blood 
stream, and thus the urea goes all over the body, to be 
finally sorted out from the blood by the kidneys. A sample 
of urea can be purchased at any well-stocked drug store. 


274 


HYGIENE BY EXPERIMENT 


A. What is the appearance of urea crystals? 

B. Under what conditions would there be likely to be 
a large amount of urea in the urine? 

4. Some minor forms of waste. There are various 
minor forms of waste coming from the body, only two 
of which you will have a chance to consider here. 

A. Examine a specimen of bile, as from a chicken’s 
liver, for bile is partly a form of waste. Where is bile 
stored, and what is its appearance? 

B. The indigestible parts of all foods pass along the 
food canal and collect in the terminal part of it, where 
the waste then takes the name feces. Why are the feces 
of vegetable-eating (herbivorous) animals less offensive in 
smell than those of meat-eating (carnivorous) animals? 

Exercise III. Exits of Body Waste 

1. Examining a kidney. Secure a specimen of a hog’s 
kidney and cut it in halves the flat way. Notice the cen¬ 
tral chamber of the kidney where the urine first collects. 
Notice also several little pyramid-shaped, lighter-colored 
bodies that point toward the central chamber from the 
outer part of the kidney. These are made up of numerous 
fine tubules that collect the urine from the blood. The 
central chamber of the kidney is drained off at one side 
by a tube leading to the bladder, where the larger mass 
of urine is collected. 

From previous study you know that urine is made up 
of water and urea. It also contains some other wastes, 
such as uric acid and various salts. 

A. In your notebook make a sketch or drawing of the 
inside of a kidney. 

B. What are at least four of the forms of waste that 
the kidneys throw off? 


BODY WASTE 


275 


C. The blood comes to the kidneys almost directly 
from the lungs, where it has lost its excess of carbon 
dioxid, and the kidneys take out the two remaining 
major forms of body waste; namely, water and urea. In 
what veins, then, would you expect to find the most 
nearly pure blood? 

D. Why is it so exceedingly important to keep the 
kidneys in healthy condition? 

E. What is Bright’s disease? 

2. The lungs as organs of elimination. See Studies 
Thirty-six and Forty-one. 

A. What forms of body waste are thrown off by the 
lungs? 

B. What proportion of its load of .carbon dioxid does 
the blood give up as it passes through the lungs? 

C. Of the air you exhale, what proportion is carbon 
dioxid? 

D. What is the highest percentage of carbon dioxid 
that there may be in the air, leaving it fit for breathing? 

3. The skin as an organ of elimination. See Studies 
Forty and Forty-one. 

A. In the incidental work of the skin, what three 
forms of waste matter are thrown off? Name them in 
order of their importance. 

B. Why do the kidneys have to discharge less water 
on warm days than on cold days? 

4. The terminal part of the food canal. 

A. How frequently should you discharge the feces? 

B. Why is constipation so undesirable a condition? 

C. Why is eating an excess of protein undesirable? 

D. What is an important reason why you should drink 
plenty of water? 

5. The liver as an eliminative organ. 


276 


HYGIENE BY EXPERIMENT 


A. What form of waste is manufactured and thrown 
off by the liver? 

B. Where is the waste stored before it is thrown off? 

C. Where does this storage organ empty its waste? 

Exercise IV. Questions for Investigation 

1. What is meant by the expression “food is oxidized 
in the body”? 

2. What is the principal use of protein in the body? 

3. What are the three principal forms of waste prod¬ 
ucts from the body? 

4. Where are the kidneys located? 

5. What are the principal functions of the kidneys? 

6. When more carbohydrates or fats are eaten than 
are needed by the body, what becomes of the excess? 

7. Where is the protein food mainly stored in the 
body? 

8. Why do famine sufferers become so emaciated? 

9. If more protein is eaten than the body needs, what 
becomes of it? 

10. How do proteins from meats compare with those 
from vegetables in nourishing power? 

11. What is gelatin, and what is its food value? 

12. What are four reasons why you should not eat 
much meat? 

13. Why does a boy or girl require as much food as 
an adult? 

14. Do most boys and girls eat too much food, or not 
enough? 

15. What are the foods upon which you can mainly 
depend for your supply of energy? 

16. What should be the difference between a winter 
and a summer diet? 


BODY WASTE 


277 


17. What is the chief source of supply for the body’s 
need of minerals? 

18. What are vitamins, and what foods yield them? 

19. Why is milk so important a part of a healthful diet? 

20. Why should you not eat a large amount of sugar 
or sweets? 

21. How much fat should be included in the daily 
ration? 

22. Why should you eat plenty of coarse vegetables? 

23. What are three good rules for a proper diet? 

24. Why is constipation a serious enemy of mankind? 

25. What are some foods that will help to relieve con¬ 
stipation? 

26. How will a knowledge of foods help one to gain 
health and to save money at the same time? 

27. What are some good habits to form with respect 
to getting rid of your body wastes? 


STUDY FORTY-THREE 

BONES AND JOINTS 

When your fathers and mothers went to school and 
studied physiology, the schools paid a good deal of 
attention to teaching the names of the bones of the body. 
Because learning a list of bones was found to be pretty 
uninteresting work, some people have taken the extreme 
view that the bones should be studied scarcely at all. 
However, a study of the human body without attention 
to the skeleton would be as absurd as the study of an 
automobile without regard to the chassis. 

Exercise I. Studies of Bones 

1. The bones of your skeleton. By feeling the bony 
parts of your body, or by studying a mounted human 
skeleton, find out, as nearly as you can, how many dif¬ 
ferent bones there are in each of the following organs: 
the fingers and free part of the thumb; the palm of the 
hand; the wrist; the forearm; the shoulder; the head; the 
face; the chest; the backbone; the hips; the thigh; the 
leg; the arch of the foot; the toes of one foot. 

2. The structure of a bone. Obtain a fresh bone that is 
several times longer than wide, and saw it in two length¬ 
wise, using a butcher’s saw or an ordinary hack saw. 
Obtain a similar dry bone and saw it in two likewise. 
Chicken bones will do, but larger bones will be better. 
Examine your specimen and then describe the following 
parts: The membranous covering, known as the perios¬ 
teum; the shell of very hard bone on the outside, the 
compact bone; the porous bone appearing in the ends of a 
dry bone, the spongy bone; the red mass within the spongy 
bone, the red marrow; the yellowish, soft matter in the 

278 


BONES AND JOINTS 


279 



Fig. 73. These boys cleaned and mounted this skeleton of a dog. The 
job was tedious, but interesting; and the boys learned a lot about bones 
while they were at it. 


center of the bone shaft; the fatty marrow; and finally the 
space occupied by the fatty marrow, called the medullary 
cavity. 

3. Shapes of bones. In general, bones are classified 
into four different groups as to the shape — the long , the 
short , the flat and the irregular. 

A. A long bone is one that is more than twice as long 
as it is wide or thick. There are at least 60 such bones in 
your body. Where are they? 

B. A short bone is one that is less than twice as long 
as it is wide. What are the locations of some short bones? 

C. A flat bone is one that is much longer and wider 
than it is thick. Where can you find examples of such 
bones? 

D. An irregular bone is one that has dimensions that 
are not regular. A good example is a vertebra , one of the 
bones that make up the backbone or spinal column. 










28 o 


HYGIENE BY EXPERIMENT 


Secure a dry vertebra of some animal and examine its 
biggest part, the body , and the pointed parts, the pro¬ 
cesses. What are the uses of the following: the body, the 
processes, and the hole through the middle? 

4. The composition of bones. Into a wide-mouthed 
bottle put a small piece of limestone or marble and pour 
over it a 20 per cent, solution of dilute hydrochloric acid. 
Into another bottle put a reasonably fresh drumstick of a 
chicken, and cover it also with a 20 per cent, solution of 
hydrochloric (muriatic) acid. Let both stand for a day. 

A. What happened to the limestone kept in the acid? 

B. What happened to the chicken bone kept in the 
acid? 

C. How can you now tie a knot in the chicken bone? 

D. What was taken out of the bone was called mineral 
matter and what remained is animal matter. What does 
the mineral matter seem to do for a bone, and what does 
the animal matter seem to do? 

Exercise II. Studies of Joints 

1. Examining a joint. Obtain a fresh hip joint of a 
pig or other animal. If the outer sheathlike covering is 
still on, examine it to see how the joint is protected. 
Now remove this sheath by suitable cutting, and note the 
smooth coverings of the bone ends. The material that 
covers the bone ends is called cartilage. 

A. How does cartilage differ in at least three ways 
from compact bone? 

B. Where in the human body can you locate specimens 
of cartilage? 

C. Why does a joint work so easily? 

2. Nature and use of ligaments. Find in your speci¬ 
men of a joint the white cords, called ligaments , that help 


BONES AND JOINTS 


281 


to tie the bones together. Separate one of these out and 
see how a ligament differs from cartilage and from bone. 
Also find any similar white cords, known as tendons , 
that were fastened at one end to the bone and at the other 
end to a muscle. You can feel such cords at the back of 
your own knee. 

A. A ligament and a tendon differ from bone in what 
ways? 

B. A ligament and a tendon differ from cartilage in 
what ways? 

C. A ligament differs from a tendon in what way? 

3. Kinds of joints. We are accustomed to describe 
different kinds of joints by the motions they permit. If 
the motion is like that of a hinge, as in the knee, it is 
called a hinge joint. If two nearly flat surfaces pivot, as 
in the neck, the joint is called a pivot joint. If a joint 
permits a conelike motion and also lets one bone rotate 
or twist on the other, as in the shoulder joint, it is 
called a true ball-and-socket joint. If it permits a conelike 
motion but does not let one bone turn or twist on an¬ 
other, as in the wrist joint, it is called a false ball-and- 
socket joint. Now proceed over the body to find all the 
examples of these joints you can. How many of each can 
you locate? Keep in mind that there is a joint between 
the wrist ends of the forearm bones, and that there are 
two distinct kinds of joints at the elbow — one for each 
of the forearm bones. 

4. Obtaining a skeleton. It is possible to illustrate 
many important facts about the framework of an animal 
by using the skeleton of a dog or other small animal, such 
as you yourself can mount. It will take some chemicals 
and a little work to prepare such a skeleton, but you will 
be proud of the result. Your mounted specimen should 


282 


HYGIENE BY EXPERIMENT 


be properly labeled and left in your school museum. See 
Figure 73. By turning to page 23 of Hartman’s Labora¬ 
tory Manual of Human Physiology , you will find complete 
directions for freeing a skeleton of its flesh, and for 
mounting the bones. 

What success have you had in mounting the skeleton 
of an animal? 

Exercise III. Questions for Investigation 

1. What is a skeleton, and what is the origin of the 
word “skeleton” ? See the big dictionary. 

2. What bones make up the spinal column? 

3. Why would it be particularly dangerous to a baby 
if any weight were to fall on top of its head? 

4. How many pairs of ribs have you? 

5. What is the scientific name for the breastbone? 

6. What two bones make up the shoulder bones? 

7. What are the pelvic bones? 

8. What are the bones in your arms? 

9. What are the bones in your thighs and legs? 

10. What two kinds of matter make up bony tissue, 
and how do they differ from each other? 

11. What is a true joint? 

12. What is cartilage? 

13. What is a ligament and what is a tendon? 

14. Why is it important to take good care of a sprain? 

15. What is a dislocation? 

16. What should one do in case of a broken bone? 

17. Why do the bones of children need special care? 

18. Why do the bones of old people need special care? 

19. What are some good habits to have in order to 
keep bones and joints in good condition? 

20. What are some practices to avoid, if a good body 
framework is to be preserved? 


STUDY FORTY-FOUR 

MUSCLES: POSTURE, EXERCISE, AND FATIGUE 

There is a saying that “a noble soul dwells in a strong 
body/’ It is true, of course, that many a noble soul has 
dwelt in a weak body, and that many a mean spirit has 
dwelt in a strong body. But most of those who have made 
the world a little better than they found it, have been men 
and women of sound physique. Think of the names of a 
dozen famous men, about whose lives you have read. 
Most of them, like George Washington, had more than 
ordinary physical vigor. It is clear that if you are to do 
your best, you must have health and strength. How are 
you to attain these, and how are you to retain them? 
To begin with, a knowledge of the facts about the work¬ 
ings of the muscular system is highly important. 

Exercise I. Studies of Muscles 

1. Examining a muscle. From a chicken or other 
small animal take a whole muscle with its tendons, and 
note the difference between the body of the muscle and 
its tendons. Also note how the tendons connect with 
both the muscle body and the bone. 

A. The body of a muscle differs in what ways from its 
tendons? 

B. To what does a tendon usually tie a muscle? 

2. Studying muscle tissue. Take a specimen of boiled 
beef and examine its structure. You will readily see that 
it is made up of little bundles of muscle tissue each about 
as big across as a match stem. Now take one of these 
bundles and pick from it the tiniest possible thread, as 
small at least as a fiber of cotton or of silk. Such a 
thread, if examined under a microscope, will be found to 

283 


284 


HYGIENE BY EXPERIMENT 



Fig. 74. The ergograph. This is the fatigue-testing machine that can 
be made. The metronome should be set to tick sixty times a minute. 

consist of several still finer threads, called muscle fibers. 
If possible, mount one of these fibers under a compound 
microscope. What is the appearance of a boiled muscle 
fiber when seen under a microscope that magnifies 100 to 
500 times? (See Figure 38.) 

Exercise II. Studies of Posture 

1. Review. Recall or reproduce the studies of posture 
in Study Two. What do you learn from your review of 
that Study? 

2. Your posture diagram. Send to the American 
Posture League, 1 Madison Avenue, New York City, for 
a chart of posture. Make a diagram representing your own 
posture. (See Figures 3, 4, and 5.) What can you do to 
correct the imperfections of carriage you may have, if any? 







MUSCLES 


285 


3. Studying your footprint. If you have not already 
done so, take a footprint as directed in Study Two. 
Paste your footprint impressions in your notebook and 
consider how you can improve your feet, if they are 
not as they should be. 

Exercise III. Studies of Exercise and Its Effect 

1. Reporting your condition. After you have been 
comparatively quiet for a time, count your pulse and 
breathing-frequency for a minute, and take note of your 
temperature, blood distribution, perspiration, relative 
quantity of air you naturally breathe at a breath, and 
how you feel. Now run for a tenth to a fifth of a mile, or 
around a city block, and at once reexamine yourself on 
all points listed above. Fill out the table below. 


Record of 

First Measurement 

Second Measurement 

Pulse 

Breathing rate 

Seeming temperature 

Blood distribution 

Air breathed at a breath 

Feeling of well-being 
















2. Use of valves in veins. Recall or repeat the seventh 
experiment under Exercise I of Study Thirty-eight. 

A . What happens to the blood in a vein when pressure 
is applied at a point on the vein? 


















286 


HYGIENE BY EXPERIMENT 


B. How does exercise serve to pump blood along in the 
veins that are in muscles? 

3. The value of exercise. Place in a wash basin full of 
clean water, sponges that have just been soaked with dirty 
water. Squeeze one of these sponges repeatedly while 
it is under the water in the pan, and then remove both 
sponges. Compare the cleanliness of the two sponges, by 
observing the condition of the water you can now squeeze 
from each. 

We shall presently find that muscles accumulate waste 
matter when they are made to work vigorously. If a 
muscle has fatigue waste in it, vigorous rubbing and 
squeezing of the muscle will help to clear it of its waste. 
This rubbing and squeezing process is called massage. 

A. How does exercise serve to clear the muscles of 
waste material? 

B. Why cannot medicine ever take the place of exer¬ 
cise? 

C. Can automobile riding take the place of vigorous 
exercise for maintaining high vitality? 

D. Why is massage helpful in reducing stiffness, after 
vigorous exercise ? 

Exercise IV. Fatigue Experiments 

1. Taking a fatigue record. For taking a fatigue record 
there will be needed a fatigue machine such as is shown 
photographically in Figure 74 and diagrammatically in 
Figure 75. A more nearly perfect machine is one known 
as Gregg’s Ergo graph, to be had from the C. H. Stoelting 
Co., Chicago, Illinois. In the experiment itself, the one 
whose record is to be taken sits by the apparatus, his right 
hand and elbow resting as shown in Figure 75. The mid¬ 
dle finger is trust through the leather or cloth loop, which 


MUSCLES 


287 


in turn is tacked to the left-hand end of the weight carrier. 
Tie the index finger firmly in place. Now put two pounds 



Fig. 75. An ergograph or fatigue apparatus as it may be constructed by 
members of the class. 


of weight into the bucket and let the experimenter lift 
the weight with his middle finger only, as far as he can, 
once every second. Meantime, the operator will have 
to turn the windlass slightly each instant the finger of the 
experimenter lets the load drop back. This is to cause the 
record board to pass under the pencil point. The record 
that is made in a minute to 60 strokes of the metronome 
should taper from broad strokes—almost across the sheet 
at first—to a thin point which indicates arrival at fatigue. 
If the record is not like this, increase or lessen the 
weight in the bucket and try till such a record results. 
The idea is to see what is the heaviest weight you can 











































































































































288 


HYGIENE BY EXPERIMENT 


carry and reach the state of fatigue in about a minute. 
Paste your fatigue record in your notebook. 

2. The effect of rest periods. After several hours’ rest, 
repeat the fatigue experiment, but this time lift the former 
load once in two seconds instead of every second, and 
continue for two minutes. 

A. Paste your record in your notebook. 

B. Why did you not reach a state of fatigue this time 
as you did before? 

Exercise V. Questions for Investigation 

1. Of what is a muscle composed? 

2. How do muscles move the body? 

3. What is a tendon? 

4. How do you manage to walk? 

5. What is the difference between running and walk¬ 
ing? 

6. How is the trunk held erect? 

7. How is the head held erect? 

8. How can you stand erect? 

9. Give five rules for good posture in standing and 
walking. 

10. What is the vertical-line test for posture? 

11. What is flat-footedness? 

12. Just where is the difficulty in a case of flat- 
footedness? 

13. How is flat-footedness to be corrected? 

14. What should be the position or direction of the 
foot in standing? 

15. What should be the position or direction of the 
foot in walking? 

16. What health habits should you observe in respect 
to posture, exercise, and fatigue? 


STUDY FORTY-FIVE 

BEHAVIOR AND THE NERVOUS SYSTEM 

Why do people behave as they do? Why do they 
laugh or cry, get angry or control themselves, flee from 
danger or else meet it courageously? Why do they do 
any of their many acts? Such questions have doubtless 
puzzled you. Whatever the final answers may be, they 
will have to be sought in a study of the mind and the 
nervous system. The more you know about the mind 
and the wonderful nervous system by which your body 
is controlled, the more you will come to understand your 
own behavior and that of other people. 

Exercise I. Studies of Behavior 

1. Reflex acts. Recall your behavior on touching 
something hot. 

A. Did you have to think about jerking your hand 
back? 

B. If you tickle a sleeper’s toes, will he move before 
he awakens? 

C. What are reflex acts? Give examples. 

2. Instinctive behavior. Recall your behavior when 
you suddenly came upon a snake, if you are afraid of 
snakes. 

A . Did you have to know there was something to be 
afraid of before you ran? 

B. Did you have to think at all while you were 
scared ? 

C. Was your behavior simple, or were there a lot of 
acts going on at the same time? 

D. Fighting, crying, being curious, and “showing off” 
are instinctive acts. In the light of the answers to Ques- 

289 


290 


HYGIENE BY EXPERIMENT 



Fig. 76. An immigrant woman and her two sons. The man at the left 
has been in the United States for a number of years, while the one at 
the right has just landed with his mother. These men, of the same 
heredity, have had very different concerns in life—their behaviors have 
been different—and the story of each of them is rather plainly written 
on his face. 


tions A, B, and C, what definition can you give for the 
term “instinct”? 

E. How does instinctive behavior differ from reflex 
action ? 

3. Voluntary behavior. Play a game of “Simon-says- 
thumbs-up.” If you do not know this game, ask some 
older person how to play it. While playing the game, 
consider how you get your hands to do just what they 
ought to do. 

A. What is it you have in mind when your hands 
come up at the time they should stay down, in a game of 
“Simon-says-thumbs-up” ? 

B. What is really in your mind when the hands stay 
down both when they ought to and when they ought 
not to? 



BEHAVIOR AND THE NERVOUS SYSTEM 


291 


C. What seems to precede every willed act? 

D. How does such an act differ from a reflex act? 

E. How does such an act differ from an instinctive act? 

4. Habits. Whistle or sing, and draw a picture at the 

same time. 

A. Which of the two acts do you think about the 
more and why? 

B. What is a habitual act? 

C. How does such an act differ from the other three 
forms of behavior mentioned: namely, reflexes, instincts, 
and deliberate or idea-controlled acts? 

Exercise II. Examining the Brain 

1. The parts of a brain. Secure as complete a speci¬ 
men as possible of a sheep’s or a hog’s brain with as 
much spinal cord still attached as may be. Any quadru¬ 
ped’s brain will serve. Wash the specimen thoroughly 
after removing the covering membrane, if there is any, 
and put it to soak for several days in a 10 per cent, solu¬ 
tion of formalin. When ready to study it, remove and 
wash thoroughly in water. Examine the specimen until 
you become reasonably well acquainted with its more 
important parts, such as the cerebrum or larger portion, 
with its parts separated by a deep fissure; the cerebellum 
lying just behind and partly under the cerebrum; the 
medulla lying behind and under the cerebellum and con¬ 
necting directly with the stump of the spinal cord , which 
is the part of the nervous system found in the spinal 
column. On the underside of the center of the cerebrum 
find the roots of the optic nerves; under the medulla find 
the roots of several other nerves. 

In the figures that follow, or on drawings made from 
them, label the parts of the brain that have been named. 


292 


HYGIENE BY EXPERIMENT 



Figs. 77, 78, and 79. The brain of a sheep: top, underside, and 

cross section. 


2. The inside of a brain. Place the brain so that its 
forward part will be turned toward you, and its upper 
side uppermost. You have already found a long fissure 
separating the two halves of the cerebrum. With a sharp 
knife, at right angles to the big fissure, cut down through 
the brain a third of the way to the rear of its forward end. 
When cut, the surface should look like that in Figure 79. 
Note the gray surface of the cerebrum, known as the 
cortex or gray matter. This gray matter is believed to be 
the seat of the thinking part of the brain — the place 
from which voluntary acts are directed. 

You should find two circular masses of gray matter 
near the center of the brain, each called a thalamus 
(plural thalami). The thalami are supposed to be the seat 
of agreeable and disagreeable feelings, and of instinctive 
actions. The cerebellum, working in connection with 
the fore brain, has a good deal to do with habits, it is 
believed. The medulla and the spinal cord take care of 
reflex acts. The nerves, of course, carry nerve messages. 

On a copy of Figure 79 in your notebook, write at one 









BEHAVIOR AND THE NERVOUS SYSTEM 


293 


side the names of the parts of the brain that have been 
mentioned in the paragraph above, and on the other side 
write the use of each of the parts. 

3. The development of animal brain. Study the five 
types of brain models shown in Figure 26. You will 
notice that a fish brain has only a very small cerebrum 
but relatively large parts below the cerebrum. Remem¬ 
bering that the cerebrum is the seat of acts that are 
learned, and that the parts below are the seat of un¬ 
learned forms of behavior, you can now understand why 
it is difficult to teach a fish anything. Nearly all its acts 
are the things it simply has to do. 

Following the series of pictures of brain models along 
from fish to man, you will note that the cerebrum of 
each is increasingly large. You will also recall that a 
frog can learn more than a fish, though not very much 
more, an alligator more than a frog, a dog much more 
than an alligator, and a man incomparably more than a 
dog. Having a large cerebrum enables a creature to 
perform a great variety of acts and gives it a larger 
control over its living conditions. 

A. What three forms of behavior in general are alike 
in man and in the lower animals? What form of be¬ 
havior in man is almost absent among the lower animals? 

B. Why is this so, as you judge from the series of 
brain models shown in Figure 26? 

4. Explaining human behavior. In order to get a little 
further into the question as to why people do what they 
do, you need to examine Figure 80. After studying the 
diagram carefully, try to answer the questions following 
it, bearing in mind that the purpose of the cerebrum, 
or upper part of the human brain, is to control, or hold in 
check, the thalami and the lower parts of the brain. 


294 


HYGIENE BY EXPERIMENT 


A. Why is a very young child’s behavior more like 
that of a lower animal than like that of an adult? 


Will 

Attention 

Thinking 

Judging 

Conceiving 

Knowing 

Remembering 

Imagining 

Sensing 

Habits (in part) 

Conduction 
Sight reflexes 
Hearing reflexes 

Habits (in part) 
General reflexes 
Conduction 



Protection 
Sex maturing 

Subjection (shame) 
Herd tendencies 


j Collection 
\ Construction 

/ Assertion (pride) 
\ Curiosity- 


Suggestion 
Imitation 
Laughing 
Repelling 
Fighting 
Fearing 
Feeding 
. Crying 


Fig. 8o. The center of the nervous system, showing the parts and 
their functions, and the ages when the instincts develop. 


B. When men get drunk, the alcohol affects the cere¬ 
brum first and dulls their wits in a little while. Why does 
a drunken man act like a lower animal? 

C. When people grow very old, sometimes the upper 
part of the brain (the cerebrum) begins to go to pieces 
first; that is, it loses the impressions made by experi¬ 
ence. Why do some very old people grow “childish”? 

Exercise III. General Questions 

1. What are the parts of the nervous system? 

2. What are the two great functions of the nervous 
system ? 

3. What is the nervous system made up of? 

4. What is a motor nerve? 

5. What is a sensory nerve? 

6. How heavy is the human brain? 

7. What are its three principal parts? 












BEHAVIOR AND THE NERVOUS SYSTEM 


8. How does the surface of the brain differ from the 
interior? 

9. What is the use of the cerebrum? 

10. What is the use of the cerebellum? 

11. What is the use of the thalami? 

12. What is the use of the medulla? 

13. What is the use of the spinal cord? 

14. Why are sleep and rest necessary? 

15. How many hours of sleep should you have at 
your age? 

16. What are some good rules for acquiring a helpful 
habit? For getting rid of a bad one? 

17. If a child lets itself get angry easily all through 
childhood, what kind of disposition will it have when 
grown up? 

18. If a boy or girl does not control his or her appe¬ 
tite when young, what is to be expected of the adult? 

19. If a boy or girl is selfish in childhood, what will be 
true of the adult? 

20. Why is it important that you learn to control 
your instinctive tendencies as early in life as possible? 

21. What are some of the means that will aid you in 
controlling your instinctive or animal tendencies? 

22. What are some good-health habits you have 
decided to practice as a result of your study of behavior 
and the nervous system? 


STUDY FORTY-SIX 

THE SENSES AND THEIR MEANING 

A boy living on the Western plains had been warned 
many times by his parents to watch out for rattlesnakes. 
One day when he was going across a prairie to look after 
some cattle he suddenly noticed what he thought was a 
rattlesnake lying at his feet, and he turned instantly and 
ran toward home. The coiled-up thing on the prairie 
might have been a rope, a whip, or a harmless snake, but 
the boy did not stop long enough to see. He did not use 
his senses. He acted only instinctively. His thalami and 
his instincts had been implanted in him for just such a 
situation, and in this case may have saved his life. 

But he had been given his senses and his enlarged 
cerebrum to help him get a fuller knowledge of what 
was around him, so that he need not always act in¬ 
stinctively. A closer observation and a larger experi¬ 
ence with coiled-up things might have saved him a 
race for home and have restored his father’s blacksnake 
whip lost on the prairie. You are now to study the senses 
with which he was endowed, and which he might have 
used with greater thoughtfulness. 

Exercise I. Studies of Skin Senses and Muscle Senses 

i. The skin sensations. To find out what are the four 
different kinds of sensations connected with the skin, 
make use of a pencil and pin as directed. Warm the 
pencil, and with its point explore a square inch on the 
front of your wrist to find tiny spots that seem warmer 
than other places. Make the pencil cold and hunt for 
corresponding cold spots. Have the pencil neither hot 
nor cold and try this time to find spots that are 

296 


more 


THE SENSES AND THEIR MEANING 


297 



Fig. 81. Models of sense organs, the parts of which may be separated 

for study, will be found helpful. 


sensitive to touch than other spots. Using a pin point, 
gently hunt for places a little more sensitive to pain than 
other places. What varieties of sensation have you 
found on a square inch of your skin? 

2. The muscle sense. Put your open hand behind 
your head without touching it. You will know, of course, 
what shape your fingers are in, but now stiffen your 
fingers and see if there is a more certain knowledge of the 
position of your hand and fingers. What you get is a 
sensation of strain due to the pressure of the contracting 
muscles on the special nerve endings that carry the 
muscle sense. This is one of the most important of all 
your senses. Helen Keller, blind and deaf, depends upon 
this sense more than upon any other except touch for 
what she knows of the world in which she lives. 

A. What is the muscle sense? 

B. Of what use is it to you? 














298 


HYGIENE BY EXPERIMENT 


Exercise II. Smell and Taste 

1. Smell sensations. After your teacher has put some 
odorous substances separately in cloth-covered, paste¬ 
board boxes, see if yt>u are able to say what the inclosed 
substances are. 

A. How many substances were there to tell by the 
smell in your experiment with odors, and how many of 
these did you identify? 

B. In your judgment, are the varieties of smell sensa¬ 
tions fewer or more numerous than the skin sensations? 

2. The taste senses. To get the experience of the four 
tastes the tongue can distinguish, put some sugar or 
candy at one place and another on the tongue to deter¬ 
mine just where it can best tell sweetness. Similarly try 
a sour substance like “sour drops” of candy; a salty sub¬ 
stance, such as common salt; and finally a bitter sub¬ 
stance, such as quinine sulfate. 

What different parts of your tongue seem best adapted 
to each of the elementary taste sensations? 

Exercise III. The Ear and Hearing 

1. The outer ear. The external ear consists of the 
organ at the side of the head commonly called the “ear” 
(the auricle ), and the tube leading into the head (the 
auditory canal). In your notebook make a sketch of an 
auricle, labeling the outer rim helix , the inner ridge anti¬ 
helix, the central depression concha, and the lower lobe 
lobule. 

2. Function of the outer ear. Let some person standing 
several feet behind you call out a word with equal force 
under the following conditions: (1) while you hold your 
hands vertically, palms backward, one at each side of 
your head, and just in front of your auditory canals; 


THE SENSES AND THEIR MEANING 


299 


(2) while you hold your hands one just behind each au¬ 
ricle; (3) while your hands are removed. Repeat several 
times, if necessary, to make sure of the correctness of 
your answers to the questions that follow: 

A. In what position of the hand can you hear best? 

B. Why is this so? 

C. What, do you judge from your experiments with 
your hands, is the use of your auricles? 

D. What part of the auricle is most useful in hearing? 

3. The whisper test for hearing. With pupils seated so 

the right ear is toward the tester, who stands 20 feet away, 
let the tester whisper with uniform loudness a series of 
20 non-consecutive numbers between 10 and 99. Let the 
members of the group record the numbers as they under¬ 
stand them. The numbers are now to be read aloud by the 
tester, while the pupils set down the correct list and record 
the percentage of correct hearings. 

The pupils are next to present their left ears to the 
tester for a similar test with a new series of numbers. 
Records are to be made as before. 

Exercise IV. The Eye and Vision 

1. The coats of the eyeball. To get a fair under¬ 
standing of the eyeball, you should study its coats, one 
by one, from a real specimen of the eye of a large animal, 
such as a beef. There are three of these coats. 

A . To study the external coat, clear away all muscles 
and connective tissue from the eyeball down to the tough 
gray outside portion, known as the sclerotic coat, which 
covers the rear four fifths of the eyeball. Now make a 
small cut in the center of the rear part of the sclerotic 
coat, being careful not to cut through into the black coat 
beneath, if this can be avoided. With pointed scissors 


300 


HYGIENE BY EXPERIMENT 


make a cut forward to the center of the clear or colored 
part of the eye, holding the scissors in such a way that the 
under point is kept against the underside of the outer 
coat, thus preventing the puncturing of the black coat 
beneath. Now, similarly, make another cut forward at 
right angles to the first cut, so as to make a sector of the 
sclerotic coat, which is then to be peeled forward. The 
front one fifth of the outer coat of the eye is called the 
cornea. How does the cornea differ in three ways from 
the sclerotic coat? 

B. The middle coat of the eyeball is* made up of three 
parts. The first of these is the black coat underlying the 
sclerotic, called the choroid coat. By pulling at it with 
pliers (in a way not to break the gray retina beneath) 
discover its thickness and structure, as compared with 
the thickness and structure of the sclerotic coat. Note 
two ways in which the choroid coat differs from the scler¬ 
otic coat? 

The second portion of the middle coat of the eyeball is 
called the iris. It is a circular membrane with a hole in 
the middle, and it may be seen attached to the forward 
border of the choroid coat. Describe the iris and the 
pupil. 

The third portion of the middle coat of the eyeball may 
be seen by tearing away the exposed part of the iris, and 
finding back of it numerous black folds known as the 
ciliary processes. Together these make a circular, fringe¬ 
like belt behind the iris. Record in your notebook what 
you have learned about the ciliary processes. 

C. The inner coat of the eyeball is called the retina. 
Carefully pull away the black middle coat of the eye 
from rear to front of the opening you made, so as to ex¬ 
pose more fully the delicate, gray retina. Only patches of 


THE SENSES AND THEIR MEANING 


301 


it may be left, unless the dissection has been very skill¬ 
fully done. 




Parts 
of the- 
eye 



I.Profeciive coverir 


Z,Coa\ 


5 


External 


Middl< 


Internal, 
or. Retina 


5cle rotic 
Corne a 


Choroid 


^-Refracting parts 
A. Optic nerve — 


Center of 
Blind spot 
General retina 

Aqueous humo 
Crystalline len 
Hyaloid membrane 
Vitreous humor 


Fig. 82. The parts of the eye. 


A. Does the retina go as far forward as the choroid 
coat does? 

B. Is the retina as thick and strong as the choroid coat 
is? 

C. Do you find any signs of blood vessels in the retina? 

D. Emptying the contents of the eye into a small dish 
and turning the coats inside out, to what part of the eye 
do you find the retina attached, as it now hangs down 
from this point of attachment? 

E. The attached part of the retina is known as the 
blind spot. What is the relation of the retina to the optic 
nerve and of the optic nerve to the blind spot? 

2. The inner parts of the eye. You now turn to the 
study of the inner parts of the eyeball. The larger, jelly- 
like mass thrown out in the previous study is the vitre¬ 
ous humor. Handle it, cut it, and observe its outer surface 





















302 


HYGIENE BY EXPERIMENT 


known as the hyaloid membrane. Write a brief description 
of the vitreous humor. 

The lens-shaped body lying at one side of the vitreous 
humor, and surrounded by black radiating marks left by 
the ciliary processes, is the crystalline lens. With sharp- 
pointed scissors, cut the hyaloid membrane around the 
border of the lens and remove the lens from the vitreous 
humor. Try using the lens as you would a simple micro¬ 
scope. Write a brief description of the crystalline lens. 

There is a liquid {aqueous humor) normally lying be¬ 
tween the lens and the cornea. It escaped when you cut 
the cornea and was blackened by coloring from the middle 
coat of the eyeball. Did you see any aqueous humor? 

3. Nearsightedness, farsightedness, and normal 
vision. Place 20 feet away in a good light, a Snellen 
or other eye-test chart, such as may be had of a 
physician. Read the card with one eye, and record 
the letters in the lowest line you can read without 
strain. Note the number that stands at the left of the 
lowest line read, and use it as the numerator of a frac¬ 
tion whose denominator is 20 (the 20 feet you stand 
from the chart). If the value of your fraction is one, the 

. vision is normal. If it is more than one, farsightedness 
{hypermetropia) is indicated. If the value is less than 
one, nearsightedness {myopia) is indicated. Proceed simi¬ 
larly with the other eye. Record results and conclusions. 

A. What is the strength of your right eye? 

B. What is the strength of your left eye? 

4. Astigmatism. Substitute for the Snellen or other 
card, a test card having radiating lines. Look with each 
eye separately, and note whether any of the radii appear 
darker than others. If any radii appear gray, indicate 
which ones they are by giving the number appearing at 


THE SENSES AND THEIR MEANING 303 


the ends of the lines. To normal eyes the lines all look 
equally black. If they appear considerably different, the 
eye is astigmatic. 

A. Does your right eye show astigmatism? 

B. Does your left eye show astigmatism? 

5. Review. Recall or reproduce the studies of the 
image made in an eye when seeing, as that experiment is 
described in Study Thirteen. 

Exercise V. General Questions 

• 1. What are the five most important groups of external 
senses? 

2. What are the two most important groups of internal 
senses? 

3. How many different senses have you studied? 

4. What are four different sensations you get through 
the skin? 

5. What are four different sensations you get through 
the tongue? 

6. How is the sense of smell stimulated? 

7. Why is the sense of smell an important one? 

8. What are the three main parts of the ear? 

9. What is the purpose of the outer ear? 

10. What are three important structures in the middle 
ear? 

11. What are the three important structures in the 
inner ear? 

12. How does a sound wave start a message to the 
brain? 

13. Why is earache a disease that may prove danger¬ 
ous? 

14. Why should you try to heal up a “running ear” 
quickly? 


304 


HYGIENE BY EXPERIMENT 


15. Mention four causes of ear trouble. 

16. What excites the optic nerve? 

17. How is the eye protected? 

18. How is the eyeball directed? 

19. Label the important parts of the eye in the copy of 
the diagram, Figure 82, which you are to draw in your 
notebook. 

20. What is the iris of the eye for? 

21. What is the pupil of the eye for? 

22. What is the crystalline lens for? 

23. What is meant by accommodating the eye? 

24. What is myopia? 

25. What is hypermetropia? 

26. What is astigmatism? 

27. Why should people with defective vision wear 
glasses? 

28. What are some common diseases of the eye? 

29. How should the light fall on the page when read¬ 
ing? 

30. How can one best rest the eyes? 

31. What are several important habits with respect to 
the care of sense organs? 


STUDY FORTY-SEVEN 

HEALTH PROBLEMS 



In Part Two of this book you considered the problem 
of germs and germ diseases. In Part Three you have had 
a simple introduction to the great subject of physiology, 
the science which deals with the normal workings of the 
cells. Here you have learned that unless all the cells do 
their share of work in the general division of labor, some 
difficulty will arise in the human mechanism. If a man is 
suffering from indigestion or any other disease not due 
to germs, he is said to have a physiological disease. 
Physiological diseases in large part account for the deaths 
not due to germs. 

Some interesting problems arise in connection with 
what are called mortality statistics , that is, statistics of 
the kinds of diseases and the number of people dying from 
each. For the year 1920 in those parts of the United 
States known as the registration area, it was reported that 


Fig. 83. Sixth-grade pupils who have just received their Health Cer¬ 
tificates for doing their health chores for six weeks 

305 














3°6 


HYGIENE BY EXPERIMENT 


over 800,000 people had died, and that 387,000 of these 
deaths were from germ diseases. These statistics do not 
cover those parts of the country — over two-fifths of it — 
from which no reliable statistics are obtained. 

Exercise I. Studies of Mortality Statistics 

1. Causes of deaths in the United States. Get a late 
copy of the World Almanac , the Chicago News Almanac , 
or the latest volume of Mortality Statistics issued by the 
Census Bureau, and find the figures for filling in the table 
that follows: 


DEATHS IN 

REGISTRATION AREA 

TOTAL 

PER CENT 

Germ diseases 
Physiological diseases 
Miscellaneous diseases 
Accidents 

Old age 

Total 
















2. Causes of deaths in your own state. Get a copy of 
the Health Report from your State Health Commissioner; 
and from it fill out a table on deaths in your own state. 
Let the table be like the one for deaths in the registration 
area. 

3. Causes of deaths in your own county or city. From 
your State Health Report, fill out a table on deaths in 
your own county or city. 

4. Principal germ and physiological diseases in your 
state. From your State Health Report get the mortality 
statistics for the twenty principal germ diseases and list 
them in a column on the left-hand side of your notebook. 
To the right of this column, list the twenty principal 

















HEALTH PROBLEMS 


307 


physiological diseases in order, from greatest to least. If 
you are in doubt how to classify any particular disease, 
see an encyclopedia, or consult a local physician or the 
school nurse. (See also Byrd’s Forty Notifiable Diseases.) 

5. Principal germ and physiological diseases in your 
county or city. In your State Health Report check up the 
number of deaths caused by diseases that you think are 
preventable, and determine what per cent this is of the 
total number of deaths. Do the same for the report of 
your county or city. What percentage of deaths has 
been needless in your state and county or city in the 
last year? 

Exercise II. General Questions on Mortality Statistics 

1. About how many people die every day in your state 
(a) from all causes, and ( b ) from preventable diseases? 

2. About how many people die every day in your 
county or city from (a) all causes, and ( b ) from pre¬ 
ventable diseases? 

3. How many minutes are there, on the average, be¬ 
tween the deaths of every two people dying from tuber¬ 
culosis in the registration area of the United States? 

4. What do you think is the principal reason so many 
people die needlessly in the United States every year? 

5. How many people are sick at any one time in the 
United States? 

6. About what proportion of these are needlessly sick? 

7. What is the present average length of life in the 
United States? 

8. How much greater is this average than it was 
twenty years ago? 

9. To which is the gain more probably due, the con¬ 
quest of germ diseases or of physiological diseases? 


308 


HYGIENE BY EXPERIMENT 


10. Has it been due more to the saving of child life or 
of adult life? 

11. What is the length of your own life expectancy 
now? 

12. What may you do to extend your life beyond your 
present expectancy? 

13. What is your score for hygienic living as determined 
from Appendix C? 


A FINAL WORD WITH THE BOYS AND GIRLS 

When you think of that great American, Theodore 
Roosevelt, visions of the rough rider, the hunter, and the 
explorer naturally come to mind. And with these, of 
course, go the idea of his vigor, force, enthusiasm, and 
physical fitness. It is hard to think that when Roose¬ 
velt was a boy, he was “pig-chested and asthmatic” as he 
himself has said. Indeed, his fight with asthma was the 
lognest and hardest fight he ever made. His body was 
frail, but he had a conquering spirit, and he was deter¬ 
mined to be strong like other boys. 

On the wide back porch of the Roosevelt home in New 
York City, a gymnasium was fitted up, and the boy reso¬ 
lutely set himself to the task of gaining health and bodily 
vigor. “I made my health what it is,” he has said. “I de¬ 
termined to be strong and well and did everything to 
make myself so. By the time I entered Harvard, I was 
able to take part in whatever sport I liked. I wrestled 
and sparred and ran a great deal, and although I never 
came out first, I got more out of the exercise than those 
who did, because I immensely enjoyed it and never 
injured myself.” 

Health is indeed a controllable condition, in considera¬ 
ble degree. Even though you may have nearly perfect 
health at the present time, you may lose this treasure; 
but you may do much to retain it, and even to regain it 
if lost. However, retaining is surer than regaining. You 
have been given facts in this book which have been found 
out for you at great cost of life and sacrifice. Whether 
or not you profit by these facts is for you to determine. 

309 


3io 


HYGIENE BY EXPERIMENT 


The author wishes you a long, healthy, happy, and useful 
life, and will consider himself rewarded for his labors if 
he has been able in some degree to help make these 
things possible for you. 




APPENDIX A 

A PLAN FOR A HEALTH CLUB 

The idea of good health is not an object of natural interest 
among the immature. It therefore becomes necessary to set up 
some form of artificial motivation that will stimulate the exer¬ 
cise of desirable health practices until habituation is complete. 
Inasmuch as boys and girls from nine to fifteen years of age are 
in what is known as the “gang and clique period,” it is not difficult 
to interest them in the organization of clubs or societies. Proba¬ 
bly the best means yet devised for the actual setting up of good- 
health practices among school pupils is that of organizing Good 
Health Clubs. 

The club idea has been carried to a high state of perfection by 
the Modern Health Crusade with its national program of health 
instruction in schools. Its Manual for Teachers should be in the 
hands of every teacher, and may be secured from the National 
Tuberculosis Association, 370 Seventh Avenuq, New York City. 

The following constitution for a health club is modified from 
the one prepared by the Modern Health Crusaders and from the 
plan drawn up for the pupils of the Louisville, Kentucky, schools 
by Miss Emma Dolfinger. It is submitted for the use of those 
who do not care to enter the larger organization. The “Record 
Chart of Health Chores” found in Appendix B is intended to go 
with this constitution. 

A Proposed Constitution for a Health Club 

ARTICLE I. NAME 

The name of this Club shall be-—. 

ARTICLE II. OBJECTS 

The objects of this Club shall be as follows: 

1. To aid its members in the establishment of good-health habits. 

2. To spread the knowledge of health among the members and 
others of the community. 

3. To keep good health through athletic and other kinds of 
exercise. 

4. To assist the teacher and other school officers in their work for 
the health of all school pupils. 

3ii 


312 


APPENDIX A 


5. To improve the sanitary conditions of our homes, our school 
and our community. 

6. To be loyal to the Club and its stand for clean thought, speech, 
sports, and bodies. 

ARTICLE III. MEMBERSHIP 

Section i. Who may join. Candidates for membership must 
know the Twelve Health Chores (see Appendix B), and must be able 
to show a record of having practised them at least two weeks with a 
completeness of at least three fourths. 

Section 2. Becoming a member. An eligible candidate may be ad¬ 
mitted to membership on assenting in open meeting, and with 
uplifted hand, to the following pledge stated by the presiding officer 
or organizer: “Do you promise to try to win and keep good health, 
to be honest in all your records and reports, and to be loyal to all the 
objects of the Club, in order that your country may have stronger 
and better men and women? If so, answer,‘I do.'” After the assent, 
the officer will then say, “You may now sign the Club Roll as a 
further evidence of your seriousness of purpose.” After the roll has 
been signed, the badge of membership, always the property of the 
Club, shall be attached to the new member. 

Section 3. Duties of members. It shall be the duty of each member 
to maintain a record of the daily performance of at least three fourths 
of the Health Chores; to be active in the support of the objects of the 
Club; and to obey all the rules that the Club may adopt at its regular 
meetings in which at least ten members are present. Willful neglect 
of these duties for a month or more, shall subject the offending 
member to expulsion from the Club and to the forfeiture of his badge. 

Section 4. Honors. A member continuing in good standing and 
showing a record of at least three fourths of the health chores per¬ 
formed for four weeks, shall be given one star to wear on his badge; 
performed for eight weeks, two stars; performed for twelve weeks, 
three stars; performed for sixteen weeks, four stars; and for each 
additional month thereafter, an additional star. 

ARTICLE IV. OFFICERS 

Section i. List of officers. The Officers of this Club shall be an 
adult Adviser, a President, a Vice President, and a Secretary, each 
selected for a term of twelve weeks. There shall also be a Health 
Officer, elected for a term of four weeks. 

Section 2. Duties of officers. The Adviser shall attend each meet¬ 
ing of the Club, or be represented by another responsible adult. He 


APPENDIX A 


313 


shall act only in an advisory way. The duties of the President, 
Vice President, and Secretary shall be those common to such officers 
in other societies. The Health Officer shall keep posted on the 
blackboard of the schoolroom, or elsewhere, the temperature of the 
schoolroom at various hours of the day and shall try to secure a con¬ 
stant temperature of 68° F. He shall see that the schoolroom is aired 
at proper times, and shall perform such other duties as are from 
time to time assigned to him. 

ARTICLE V. MEETINGS 

Section i. Time of meetings. The Club shall hold regular meetings 
once a month. Special meetings may be held at such other times as 
may be voted at a regular monthly meeting or called by the Adviser. 

Section 2. Contesting groups. The Club membership shall be 
divided by the Adviser into two as nearly equal groups as possible, 
which shall take turns in providing programs for the meetings and 
may engage in health-chore and other health or membership contests. 
The groups may work on various projects, such as entertainments, 
dramatizations, toothbrush drills, first-aid exhibitions, sanitary- 
district supervision, anti-rat, anti-fly, anti-mosquito, or other cam¬ 
paigns. 

Section 3. Procedure for a meeting. 

1. Meeting called to order by the presiding officer. 

2. Roll called by Secretary, who records the total number of 
health chores performed since the last meeting as reported by each 
member when his name is called. 

3. Reading and adoption of the minutes of the last meeting. 

4. Reports of committees and attention to unfinished business. 

5. Taking up new business, awarding stars, electing officers, etc. 

6. Admission of new members into the Club. 

7. Program of about twenty minutes’ duration on some health 
topic. 

8. Adjournment. 

ARTICLE VI. AMENDMENTS 

This constitution may be amended if an announcement is made at 
a regular meeting and voted on at the next regular meeting with at 
least twice as many voting for it as against it. 


APPENDIX B 


Health Chores and Record Chart 

I. WATER 

Drink one or more glasses of water with each meal, but not to 
wash down the food. 

2 . MILK 

Sip at least two glasses of milk each day, but drink no tea or 
coffee. 

3. FRUIT 

Include fruit or leafy vegetables in the day’s diet and chew all 
food thoroughly. 

4. TEETH 

Brush teeth thoroughly after rising and before retiring, at the 
least. 

5. PLAY 

Play vigorously, breathing fresh air deeply for at least half an 
hour. 

6. BOWELS 

Have bowel movement at least every morning. 

7. SLEEP 

Retire before 10 p. m. and rise after 7 A. M., sleeping with windows 
open. 

8. TIDINESS 

Clean the finger nails in the morning and always wash the hands 
before eating. 

9. BATHING 

Take a full bath two or more times a week. 

10 . MOUTH AND NOSE 

Keep unclean fingers and other unclean things away from mouth 
and nose. 

II. HANDKERCHIEFS 

Carry and use handkerchief properly in sneezing, coughing, and 
cleaning the nose. 


314 



APPENDIX B 


315 


12 . MENTAL ATTITUDE 

Try hard to be neat, happy, helpful, generous, and fair all 
through the day. 

My Record of Chores Performed 

Note. The form of the Record Sheet is indicated below. When 
the sheet is prepared for use, it should be extended to 
cover the rest of the months of the school year and also 
to cover each of the twelve Health Chores indicated 
above. Make an X in each day’s square for each chore 
done; half an X if chore is half done. 


Chores 

Weeks 

October 

November 

December 

S 

M 

T 

W 

T 

F 

S 

S 

M 

T 

W 

T 

F 

S 

S 

M 

T 

W 

T 

F 

S 

1 

Water 

hirst 









— 













Sec’d 





















Third 






















F’rth 






















Fifth 

— 





















2 

Milk 

First 





















Sec’d 





— 















— 


Third 




















F’rth 






















Fifth 






















3 

Fruit 

First 














— 

— 







Sec’d 




















Third 




— 


















F’rth 





















Fifth 







- 










































































































































































































































APPENDIX C 

A SCORE CARD FOR HYGIENIC LIVING 

(Slightly modified from the Curtis High-School Score Card, 

New York City) 

Note. Grade yourself on each of the items below, giving your¬ 
self as many points in proportion to the standard as you think 
you ought to have. Add the right-hand column, containing your 
credits, to find your total percentage of hygienic efficiency. 
What is your grade on hygienic habits? 

POINTS CREDITS 

Sleeping in the open, or with bedroom windows 

open. 6 

Mattress (no feathers). i 

Small pillow. i 

Bedclothing aired. I 

Arising regularly at 7 A. M. or earlier. 2 

Light exercise for at least five minutes on arising 2 

Cold bath every morning, unless ill. 7 

Hair brushed 25 strokes or more daily. 2 

Teeth cleaned at least morning and night. 6 

Individual towel. 1 

4 

Glass of water on rising. 1 

Hygienic breakfast, thorough chewing. 2 

At least one item from each of three classes of 
food: Class I, fruit; Class II, bread, cereal, 
baked potatoes; Class III, eggs, bacon, milk, 

fish, cheese. 3 

No candy or other food between meals. 2 

No active exercise for 20 minutes after a hearty 

meal. 2 

Carry books and small packages at arm’s length 

and change hands often. 1 

Use fully 20 minutes for noonday lunch. 3 

Hygienic noonday lunch, thorough chewing. ... 2 

At least one item from two classes: Class I, 
bread and butter, crackers; Class II, milk, 
soup, meat. 6 


316 






















APPENDIX C 317 

POINTS CREDITS 

Two glasses of water at lunch time or in afternoon 2 

Vigorous exercise, 30 minutes at least. 6 

Rest 10 minutes before dinner (or supper). 1 

Hygienic dinner (or supper) 

Attractive table, 1; chew well, 2; eat moder¬ 
ately, 2; at least one item from these three 
classes: Class I, potatoes, bread, macaroni, 
rice; Class II, soup, stew, roast, baked beans, 

cheese; Class III, fruit, vegetables, 3. 8 

Study or read at least 2 hours. 4 

Light behind, above, and sufficient. 3 

Retire regularly by 10 P. M . 5 

Glass of water before retiring. 1 

Clean hands, face, and mouth before retiring.. . 2 

Hygienic clothing. 8 

Correct posture. 3 

Hands and finger nails kept clean at meals. 3 

All meals at reasonably regular times. 3 


Total. 100 

For use of coffee or tea deduct 2 points per meal 
For use of alcohol or tobacco deduct 15 points 

each. 

Total minus deducl ions. 




















APPENDIX D 


APPARATUS, MATERIALS, AND SUPPLIES FOR 

THE COURSE 

I. GENERAL STATEMENT 

The following lists include articles that may well be provided 
rather early in the course for use at any time. Many of the 
items called for in the various studies of the text will be needed 
only for temporary use. These may be assembled from local 
resources at the time a study is taken up, and are not listed here. 
Money from the Junior Red Cross funds may legitimately be 
used in purchasing supplies. If such a fund is not available, a 
few health programs, dramatizations, or other pupil entertain¬ 
ments, will serve as means to secure the funds necessary for the 
successful teaching of hygiene. Once the public is educated to 
this need, boards of education will readily supply the necessities 
for such a course. 

II. EMERGENCY OUTFIT FOR THE SCHOOLROOM 

The following materials should be a part of every rural and 
city school equipment for use in first-aid work, and can be had 
from almost any drug store: 
i dozen bandages, I inch wide 
i pound absorbent cotton 
i yard of sterile gauze 

i roll of zinc oxid adhesive plaster, i inch by io yards 
i ounce flexible collodion, with brush to apply 
4 ounces of aromatic spirits of ammonia 
6 ounces of carron oil (for applying to burns) 
i box of borax 
i ounce of oil of cloves 
i paper of safety pins, small and large 

i copy of Lynch’s American Red Cross Abridged Textbook on First 

Aid. P. Blakiston’s Sons & Co., Philadelphia 

III. SPECIAL MATERIALS FOR PART ONE 

I weighing scales and i tapeline 
i homemade spirometer (see Figure io) 

318 


APPENDIX D 


319 


1 piece of rubber dam, 6 inches by 6 inches 
4 milk bottles (pints) 

Several small candles 
1 pint of limewater 

1 full set of extracted teeth got from a dentist 

2 dozen 6-inch test tubes, or small bottles 
8 ounces of hydrochloric acid 

I square foot each of cotton, linen, silk, and thin wool cloth 
1 big sheet or several “books” each of blue and of red litmus paper 
1 small bottle of alum crystals 
1 dairy thermometer 

Several simple microscopes, or reading glasses 
1 small bottle of saturated water solution of copper sulfate 
1 pint of half water and half glycerine solution of ferric chlorid 
1 small bottle of water solution of tannic acid 
1 preserved specimen of cow’s, sheep’s or dog’s brain 
1 Snellen’s or other test card for vision 
A quantity of bandaging materials 


IV. SPECIAL MATERIALS FOR PART TWO 

4 ounces of powdered sugar 
2 dozen 6-inch test tubes or small bottles 
Several simple microscopes or reading glasses 

1 compound microscope for temporary use 
8 ounces of formalin 

2 ounces of oil of cloves 

4 ounces of hydrochloric acid 
4 ounces of ammonia water 

1 big sheet or several “books” each of red and of blue litmus papei 

4 ounces of small scales of shellac 

5 cents’ worth of quicklime for making limewater 
1 small bottle of chlorid of lime 

Ten cents’ worth of flowers of sulfur 
Small bottle of hydrogen peroxid 
1 pint of denatured alcohol 
A bottle of 5 per cent, solution of carbolic acid 
1 microscopic mounting of a trichina worm 


320 


APPENDIX D 


V. SPECIAL MATERIALS FOR PART THREE 

All the materials called for in Part One 
Several alcohol lamps with wicks 

1 pint of denatured alcohol 

4 ounces of tincture of iodine 

2 ounces of sulfuric acid 
i ounce of urea crystals 

i package of pulverized cornstarch 
i carbon-dioxid generator (see Figure 58) 

1 carbon-dioxid tester (see Figure 58) 

1 syringe bulb, and rubber tubing 2 feet long 
1 balancing apparatus (see Figure 67) 

1 ventilation cabinet (see Figure 70) 

1 fatigue apparatus (see Figures 74 and 75) 

1 compound microscope with slides and cover glasses 





APPENDIX E 

REFERENCE PAMPHLETS FOR PUPILS AND TEACHER 

(For use with “Questions for Investigation”) 

1. At the beginning of the course, send to the Metropolitan 
Life Insurance Company, New York City, for their collection of 
posters, charts, and booklets on health, which they send out free. 

2. Send also to the Bureau of Education, Department of the 
Interior, Washington, D. C., for a set of their Health Education 
Series. 

3. Send to the Superintendent of Documents, Washington, 
D. C., for his price list of government publications on health. 
Ask also for the latest list of Farmers’ Bulletins. 

4. Write to the Children’s Bureau, Department of Labor, 
Washington, D. C., for its list of publications and for any free 
pamphlets which it may issue. 

5. When you have received your list of Farmers’ Bulletins, 
prepare a list of the numbers and titles of the following, with 
any additions and subtractions you may find desirable: Farmers’ 
Bulletins Nos. 142, 206, 375, 391, 444, 449, 450, 602, 607, 671, 
717, 734* 740, 754. 77L 824, 851, 896, 897, 926, 1069, 1097, 1110, 
1136. The list of bulletins changes from time to time, and only 
a late list is dependable. Send your checked list to your Congress¬ 
man, House Office Building, Washington, D. C., and if his 
supply is not exhausted he will send these to you free. If his 
supply is exhausted you may have to pay 5 cents apiece for the 
bulletins, to the Superintendent of Documents, Washington, 
D. C. But sometimes the bulletins can be had free directly from 
government bureaus. 

6. Ask your State Commissioner of Health to send such 
posters and pamphlets as he has that will be of use in teaching 
hygiene. 

7. Write to your State Veterinarian for pamphlets on tuber¬ 
culosis in domestic animals, and any other health pamphlets he 
may have. 

8. Secure the list of publications of the Tuberculosis Associa¬ 
tion of your state. 

9. Write for the health publications of the International Har¬ 
vester Company, Chicago. 


321 


322 


APPENDIX E 


10. Write for the poster pamphlet on Patent Medicines and 
Nostrums, which is issued by the American Medical iVssociation, 
Chicago. 

11. Write for the list of publications of the American 
Posture League, i Madison Avenue, New York City. 

12. Write for the list of Health Material furnished by the 
Womans Press, 6oo Lexington Avenue, New York City. The 
sets of charts on foot hygiene are very impressive and unusual. 
They cost only 20 cents. 

13. The List of Publications of the American Social Hygiene 
Association, 370 Seven;h Avenue, New York City, contains some 
invaluable suggestions on the subject of sex hygiene. 

14. Other agencies having worth-while health material are; 
the American Child Hygiene Association, Washington, D. C.; 
the Child Health Organization of America, 370 Severn h 
Avenue, New York City; and the National Health Council, 
t 71h and D Sts., Washington, D. C. 



APPENDIX F 


SUGGESTED REFERENCE BOOKS 

(For use with “Questions for Investigation”) 

B. For Pupils of Intermediate Grades and Junior High Schools. 

Bailey, R. R. Sure Pop and the Safety Scouts. World Book 
Company, Yonkers, N. Y. 

Byrd, Hiram. Forty Notifiable Diseases. World Book Com¬ 
pany, Yonkers, N. Y. 

Coleman, W. M. Handbook of the People's Health. The Mac¬ 
millan Company, New York. 

Conn, H. W. Physiology and Health (Books I and II). Silver 
Burdette & Co., Boston. 

Davison, A. Health Lessons (Books I and II). American 
Book Company, New York. 

Ferguson, H. W. A Child's Book of the Teeth. World Book 
Company, Yonkers, N. Y. 

Gulick, I. H. Gulick Hygiene Series (6 books). Ginn & Co., 
Boston. 

Haviland, M. S. Modern Physiology , Hygiene , and Health 
(3 books). J. B. Lippincott Company, Philadelphia. 

Hutchinson, W. Health Series (Books I, II, and III). 
Houghton Mifflin Company, Boston. 

Jenkins, H. D. The Perfect Gentle Knight. World Book 
Company, Yonkers, N. Y. 

Jewett, F. G. Hygiene Series (2 books). Ginn and Co., 
Boston. 

— Ritchie, J. W. New World Health Series (3 books). World 
Book Company, Yonkers, N. Y. 

Wiley, H. W. Health Series (Books I, II, and III). Rand, 
McNally & Co., Chicago. 

Winslow, C. E. A. Healthy Living (Books I and II). Charles 
E. Merrill Company, New York. 

II. For the Teacher. 

Allen, W. H. Civics and Health. Ginn & Co., Boston. (441 
pages.) 

Andress, J. M. Health Education in Rural Schools. Hough¬ 
ton Mifflin Company, Boston. (321 pages.) 

323 





324 APPENDIX F 

Andress, J. M. The Teaching of Hygiene in the Grades. 

Houghton Mifflin Company, Boston, (i77 pages.) 
Ayres, M., William, J. F., and Wood, T. D. Healthful 
Schools. Houghton Mifflin Company, Boston. (292 
pages.) 

Bancroft, J. H. The Posture of School Children. The Mac¬ 
millan Company, New York. (322 pages.) 

Brewer, I. W. Rural Hygiene. J. B. Lippincott Company, 
Philadelphia. (233 pages.) 

Broadhurst, J. Home and Community Hygiene. J. B. 

Lippincott Company, Philadelphia. (428 pages.) 

Conn, H. W. Bacteria , Yeasts and Molds in the Home. 

Ginn & Co., Boston. (295 pages.) 

Fisher, I., and Fisk, E. L. How to Live. Funk & Wagnalls, 
New York. (461 pages.) 

Hoag, E. B., and Term an, L. M. Health Work in the Schools. 

Houghton Mifflin Company, Boston. (321 pages.) 
Hough, T., and Sedgwick, W. T. The Human Mechanism. 

Ginn & Co., Boston. (572 pages.) 

Hunter, G. W. A Civic Biology. American Book Company, 
New York. (432 pages.) 

Hutchinson, W. Preventable Diseases. Houghton Mifflin 
Company, Boston. (442 pages.) 

Keen, W. W. Medical Research and Human Welfare. 

Houghton Mifflin Company, Boston. (160 pages.) 
Moore, H. H. Keeping in Condition. The Macmillan 
Company, New York. (137 pages.) 

Stiles, P. G. Hitman Physiology. W. B. Saunders Company, 
Philadelphia. (421 pages.) 

Terman, L. M. The Hygiene of the School Child. Houghton 
Mifflin Company, Boston. (417 pages.) 

Towns, C. B. Habits That Handicap. The Century Com¬ 
pany, New York. (223 pages.) 

Walters, F. M. Principles of Health Control. D. C. Heath 
& Co., Boston. (496 pages.) 

Williams, J. F. Personal Hygiene Applied. W. B. Saunders 
Company, Philadelphia. (412 pages.) 


A full index that will serve as a comprehensive key 
to the contents of this book will be supplied when 
the final edition is issued. It has been thought ad¬ 
visable to dispense with an index in this prelimin¬ 
ary edition. 




































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